anil.recoil.org
Punycode (RFC3492) in OCaml
more-spec
+3077
spec/rfc1035.txt
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spec/rfc1035.txt
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Network Working Group P. Mockapetris
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Request for Comments: 1035 ISI
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November 1987
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Obsoletes: RFCs 882, 883, 973
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DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION
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1. STATUS OF THIS MEMO
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This RFC describes the details of the domain system and protocol, and
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assumes that the reader is familiar with the concepts discussed in a
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companion RFC, "Domain Names - Concepts and Facilities" [RFC-1034].
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The domain system is a mixture of functions and data types which are an
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official protocol and functions and data types which are still
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experimental. Since the domain system is intentionally extensible, new
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data types and experimental behavior should always be expected in parts
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of the system beyond the official protocol. The official protocol parts
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include standard queries, responses and the Internet class RR data
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formats (e.g., host addresses). Since the previous RFC set, several
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definitions have changed, so some previous definitions are obsolete.
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Experimental or obsolete features are clearly marked in these RFCs, and
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such information should be used with caution.
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The reader is especially cautioned not to depend on the values which
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appear in examples to be current or complete, since their purpose is
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primarily pedagogical. Distribution of this memo is unlimited.
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Table of Contents
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1. STATUS OF THIS MEMO 1
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2. INTRODUCTION 3
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2.1. Overview 3
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2.2. Common configurations 4
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2.3. Conventions 7
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2.3.1. Preferred name syntax 7
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2.3.2. Data Transmission Order 8
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2.3.3. Character Case 9
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2.3.4. Size limits 10
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3. DOMAIN NAME SPACE AND RR DEFINITIONS 10
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3.1. Name space definitions 10
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3.2. RR definitions 11
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3.2.1. Format 11
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3.2.2. TYPE values 12
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3.2.3. QTYPE values 12
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3.2.4. CLASS values 13
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RFC 1035 Domain Implementation and Specification November 1987
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3.2.5. QCLASS values 13
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3.3. Standard RRs 13
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3.3.1. CNAME RDATA format 14
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3.3.2. HINFO RDATA format 14
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3.3.3. MB RDATA format (EXPERIMENTAL) 14
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3.3.4. MD RDATA format (Obsolete) 15
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3.3.5. MF RDATA format (Obsolete) 15
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3.3.6. MG RDATA format (EXPERIMENTAL) 16
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3.3.7. MINFO RDATA format (EXPERIMENTAL) 16
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3.3.8. MR RDATA format (EXPERIMENTAL) 17
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3.3.9. MX RDATA format 17
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3.3.10. NULL RDATA format (EXPERIMENTAL) 17
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3.3.11. NS RDATA format 18
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3.3.12. PTR RDATA format 18
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3.3.13. SOA RDATA format 19
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3.3.14. TXT RDATA format 20
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3.4. ARPA Internet specific RRs 20
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3.4.1. A RDATA format 20
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3.4.2. WKS RDATA format 21
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3.5. IN-ADDR.ARPA domain 22
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3.6. Defining new types, classes, and special namespaces 24
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4. MESSAGES 25
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4.1. Format 25
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4.1.1. Header section format 26
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4.1.2. Question section format 28
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4.1.3. Resource record format 29
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4.1.4. Message compression 30
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4.2. Transport 32
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4.2.1. UDP usage 32
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4.2.2. TCP usage 32
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5. MASTER FILES 33
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5.1. Format 33
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5.2. Use of master files to define zones 35
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5.3. Master file example 36
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6. NAME SERVER IMPLEMENTATION 37
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6.1. Architecture 37
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6.1.1. Control 37
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6.1.2. Database 37
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6.1.3. Time 39
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6.2. Standard query processing 39
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6.3. Zone refresh and reload processing 39
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6.4. Inverse queries (Optional) 40
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6.4.1. The contents of inverse queries and responses 40
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6.4.2. Inverse query and response example 41
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6.4.3. Inverse query processing 42
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6.5. Completion queries and responses 42
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7. RESOLVER IMPLEMENTATION 43
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7.1. Transforming a user request into a query 43
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7.2. Sending the queries 44
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7.3. Processing responses 46
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7.4. Using the cache 47
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8. MAIL SUPPORT 47
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8.1. Mail exchange binding 48
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8.2. Mailbox binding (Experimental) 48
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9. REFERENCES and BIBLIOGRAPHY 50
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Index 54
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2. INTRODUCTION
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2.1. Overview
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The goal of domain names is to provide a mechanism for naming resources
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in such a way that the names are usable in different hosts, networks,
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protocol families, internets, and administrative organizations.
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From the user's point of view, domain names are useful as arguments to a
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local agent, called a resolver, which retrieves information associated
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with the domain name. Thus a user might ask for the host address or
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mail information associated with a particular domain name. To enable
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the user to request a particular type of information, an appropriate
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query type is passed to the resolver with the domain name. To the user,
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the domain tree is a single information space; the resolver is
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responsible for hiding the distribution of data among name servers from
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the user.
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From the resolver's point of view, the database that makes up the domain
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space is distributed among various name servers. Different parts of the
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domain space are stored in different name servers, although a particular
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data item will be stored redundantly in two or more name servers. The
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resolver starts with knowledge of at least one name server. When the
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resolver processes a user query it asks a known name server for the
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information; in return, the resolver either receives the desired
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information or a referral to another name server. Using these
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referrals, resolvers learn the identities and contents of other name
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servers. Resolvers are responsible for dealing with the distribution of
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the domain space and dealing with the effects of name server failure by
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consulting redundant databases in other servers.
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Name servers manage two kinds of data. The first kind of data held in
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sets called zones; each zone is the complete database for a particular
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"pruned" subtree of the domain space. This data is called
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authoritative. A name server periodically checks to make sure that its
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zones are up to date, and if not, obtains a new copy of updated zones
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from master files stored locally or in another name server. The second
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kind of data is cached data which was acquired by a local resolver.
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This data may be incomplete, but improves the performance of the
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retrieval process when non-local data is repeatedly accessed. Cached
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data is eventually discarded by a timeout mechanism.
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This functional structure isolates the problems of user interface,
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failure recovery, and distribution in the resolvers and isolates the
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database update and refresh problems in the name servers.
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2.2. Common configurations
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A host can participate in the domain name system in a number of ways,
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depending on whether the host runs programs that retrieve information
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from the domain system, name servers that answer queries from other
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hosts, or various combinations of both functions. The simplest, and
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perhaps most typical, configuration is shown below:
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Local Host | Foreign
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|
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+---------+ +----------+ | +--------+
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| | user queries | |queries | | |
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| User |-------------->| |---------|->|Foreign |
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| Program | | Resolver | | | Name |
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| |<--------------| |<--------|--| Server |
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| | user responses| |responses| | |
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+---------+ +----------+ | +--------+
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| A |
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cache additions | | references |
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V | |
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+----------+ |
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| cache | |
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+----------+ |
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User programs interact with the domain name space through resolvers; the
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format of user queries and user responses is specific to the host and
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its operating system. User queries will typically be operating system
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calls, and the resolver and its cache will be part of the host operating
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system. Less capable hosts may choose to implement the resolver as a
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subroutine to be linked in with every program that needs its services.
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Resolvers answer user queries with information they acquire via queries
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to foreign name servers and the local cache.
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Note that the resolver may have to make several queries to several
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different foreign name servers to answer a particular user query, and
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hence the resolution of a user query may involve several network
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accesses and an arbitrary amount of time. The queries to foreign name
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servers and the corresponding responses have a standard format described
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RFC 1035 Domain Implementation and Specification November 1987
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in this memo, and may be datagrams.
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Depending on its capabilities, a name server could be a stand alone
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program on a dedicated machine or a process or processes on a large
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timeshared host. A simple configuration might be:
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Local Host | Foreign
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|
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+---------+ |
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/ /| |
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+---------+ | +----------+ | +--------+
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| | | | |responses| | |
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| | | | Name |---------|->|Foreign |
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| Master |-------------->| Server | | |Resolver|
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| files | | | |<--------|--| |
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| |/ | | queries | +--------+
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+---------+ +----------+ |
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Here a primary name server acquires information about one or more zones
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by reading master files from its local file system, and answers queries
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about those zones that arrive from foreign resolvers.
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The DNS requires that all zones be redundantly supported by more than
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one name server. Designated secondary servers can acquire zones and
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check for updates from the primary server using the zone transfer
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protocol of the DNS. This configuration is shown below:
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Local Host | Foreign
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|
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+---------+ |
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/ /| |
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+---------+ | +----------+ | +--------+
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| | | | |responses| | |
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| | | | Name |---------|->|Foreign |
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| Master |-------------->| Server | | |Resolver|
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| files | | | |<--------|--| |
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| |/ | | queries | +--------+
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+---------+ +----------+ |
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A |maintenance | +--------+
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| +------------|->| |
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| queries | |Foreign |
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| | | Name |
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+------------------|--| Server |
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maintenance responses | +--------+
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In this configuration, the name server periodically establishes a
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virtual circuit to a foreign name server to acquire a copy of a zone or
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to check that an existing copy has not changed. The messages sent for
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RFC 1035 Domain Implementation and Specification November 1987
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these maintenance activities follow the same form as queries and
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responses, but the message sequences are somewhat different.
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The information flow in a host that supports all aspects of the domain
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name system is shown below:
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Local Host | Foreign
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|
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+---------+ +----------+ | +--------+
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| | user queries | |queries | | |
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| User |-------------->| |---------|->|Foreign |
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| Program | | Resolver | | | Name |
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| |<--------------| |<--------|--| Server |
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| | user responses| |responses| | |
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+---------+ +----------+ | +--------+
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| A |
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cache additions | | references |
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V | |
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+----------+ |
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| Shared | |
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| database | |
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+----------+ |
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A | |
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+---------+ refreshes | | references |
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/ /| | V |
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+---------+ | +----------+ | +--------+
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| | | | |responses| | |
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| | | | Name |---------|->|Foreign |
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| Master |-------------->| Server | | |Resolver|
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| files | | | |<--------|--| |
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| |/ | | queries | +--------+
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+---------+ +----------+ |
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A |maintenance | +--------+
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| +------------|->| |
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| queries | |Foreign |
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| | | Name |
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+------------------|--| Server |
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maintenance responses | +--------+
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The shared database holds domain space data for the local name server
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and resolver. The contents of the shared database will typically be a
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mixture of authoritative data maintained by the periodic refresh
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operations of the name server and cached data from previous resolver
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requests. The structure of the domain data and the necessity for
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synchronization between name servers and resolvers imply the general
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characteristics of this database, but the actual format is up to the
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local implementor.
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RFC 1035 Domain Implementation and Specification November 1987
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Information flow can also be tailored so that a group of hosts act
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together to optimize activities. Sometimes this is done to offload less
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capable hosts so that they do not have to implement a full resolver.
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This can be appropriate for PCs or hosts which want to minimize the
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amount of new network code which is required. This scheme can also
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allow a group of hosts can share a small number of caches rather than
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maintaining a large number of separate caches, on the premise that the
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centralized caches will have a higher hit ratio. In either case,
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resolvers are replaced with stub resolvers which act as front ends to
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resolvers located in a recursive server in one or more name servers
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known to perform that service:
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Local Hosts | Foreign
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|
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+---------+ |
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| | responses |
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| Stub |<--------------------+ |
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| Resolver| | |
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| |----------------+ | |
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+---------+ recursive | | |
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queries | | |
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V | |
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+---------+ recursive +----------+ | +--------+
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| | queries | |queries | | |
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| Stub |-------------->| Recursive|---------|->|Foreign |
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| Resolver| | Server | | | Name |
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| |<--------------| |<--------|--| Server |
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+---------+ responses | |responses| | |
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+----------+ | +--------+
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| Central | |
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| cache | |
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+----------+ |
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In any case, note that domain components are always replicated for
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reliability whenever possible.
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2.3. Conventions
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The domain system has several conventions dealing with low-level, but
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fundamental, issues. While the implementor is free to violate these
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conventions WITHIN HIS OWN SYSTEM, he must observe these conventions in
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ALL behavior observed from other hosts.
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2.3.1. Preferred name syntax
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The DNS specifications attempt to be as general as possible in the rules
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for constructing domain names. The idea is that the name of any
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existing object can be expressed as a domain name with minimal changes.
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RFC 1035 Domain Implementation and Specification November 1987
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However, when assigning a domain name for an object, the prudent user
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will select a name which satisfies both the rules of the domain system
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and any existing rules for the object, whether these rules are published
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or implied by existing programs.
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For example, when naming a mail domain, the user should satisfy both the
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rules of this memo and those in RFC-822. When creating a new host name,
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the old rules for HOSTS.TXT should be followed. This avoids problems
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when old software is converted to use domain names.
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The following syntax will result in fewer problems with many
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applications that use domain names (e.g., mail, TELNET).
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<domain> ::= <subdomain> | " "
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<subdomain> ::= <label> | <subdomain> "." <label>
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<label> ::= <letter> [ [ <ldh-str> ] <let-dig> ]
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<ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
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<let-dig-hyp> ::= <let-dig> | "-"
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<let-dig> ::= <letter> | <digit>
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<letter> ::= any one of the 52 alphabetic characters A through Z in
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upper case and a through z in lower case
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<digit> ::= any one of the ten digits 0 through 9
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Note that while upper and lower case letters are allowed in domain
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names, no significance is attached to the case. That is, two names with
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the same spelling but different case are to be treated as if identical.
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The labels must follow the rules for ARPANET host names. They must
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start with a letter, end with a letter or digit, and have as interior
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characters only letters, digits, and hyphen. There are also some
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restrictions on the length. Labels must be 63 characters or less.
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For example, the following strings identify hosts in the Internet:
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A.ISI.EDU XX.LCS.MIT.EDU SRI-NIC.ARPA
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2.3.2. Data Transmission Order
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The order of transmission of the header and data described in this
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document is resolved to the octet level. Whenever a diagram shows a
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RFC 1035 Domain Implementation and Specification November 1987
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group of octets, the order of transmission of those octets is the normal
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order in which they are read in English. For example, in the following
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diagram, the octets are transmitted in the order they are numbered.
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0 1
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| 1 | 2 |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| 3 | 4 |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| 5 | 6 |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Whenever an octet represents a numeric quantity, the left most bit in
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the diagram is the high order or most significant bit. That is, the bit
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labeled 0 is the most significant bit. For example, the following
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diagram represents the value 170 (decimal).
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0 1 2 3 4 5 6 7
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+-+-+-+-+-+-+-+-+
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|1 0 1 0 1 0 1 0|
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+-+-+-+-+-+-+-+-+
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Similarly, whenever a multi-octet field represents a numeric quantity
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the left most bit of the whole field is the most significant bit. When
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a multi-octet quantity is transmitted the most significant octet is
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transmitted first.
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2.3.3. Character Case
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For all parts of the DNS that are part of the official protocol, all
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comparisons between character strings (e.g., labels, domain names, etc.)
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are done in a case-insensitive manner. At present, this rule is in
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force throughout the domain system without exception. However, future
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additions beyond current usage may need to use the full binary octet
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capabilities in names, so attempts to store domain names in 7-bit ASCII
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or use of special bytes to terminate labels, etc., should be avoided.
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When data enters the domain system, its original case should be
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preserved whenever possible. In certain circumstances this cannot be
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done. For example, if two RRs are stored in a database, one at x.y and
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one at X.Y, they are actually stored at the same place in the database,
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and hence only one casing would be preserved. The basic rule is that
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case can be discarded only when data is used to define structure in a
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database, and two names are identical when compared in a case
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insensitive manner.
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Mockapetris [Page 9]
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RFC 1035 Domain Implementation and Specification November 1987
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Loss of case sensitive data must be minimized. Thus while data for x.y
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and X.Y may both be stored under a single location x.y or X.Y, data for
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a.x and B.X would never be stored under A.x, A.X, b.x, or b.X. In
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general, this preserves the case of the first label of a domain name,
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but forces standardization of interior node labels.
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Systems administrators who enter data into the domain database should
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take care to represent the data they supply to the domain system in a
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case-consistent manner if their system is case-sensitive. The data
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distribution system in the domain system will ensure that consistent
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representations are preserved.
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517
+
2.3.4. Size limits
518
+
519
+
Various objects and parameters in the DNS have size limits. They are
520
+
listed below. Some could be easily changed, others are more
521
+
fundamental.
522
+
523
+
labels 63 octets or less
524
+
525
+
names 255 octets or less
526
+
527
+
TTL positive values of a signed 32 bit number.
528
+
529
+
UDP messages 512 octets or less
530
+
531
+
3. DOMAIN NAME SPACE AND RR DEFINITIONS
532
+
533
+
3.1. Name space definitions
534
+
535
+
Domain names in messages are expressed in terms of a sequence of labels.
536
+
Each label is represented as a one octet length field followed by that
537
+
number of octets. Since every domain name ends with the null label of
538
+
the root, a domain name is terminated by a length byte of zero. The
539
+
high order two bits of every length octet must be zero, and the
540
+
remaining six bits of the length field limit the label to 63 octets or
541
+
less.
542
+
543
+
To simplify implementations, the total length of a domain name (i.e.,
544
+
label octets and label length octets) is restricted to 255 octets or
545
+
less.
546
+
547
+
Although labels can contain any 8 bit values in octets that make up a
548
+
label, it is strongly recommended that labels follow the preferred
549
+
syntax described elsewhere in this memo, which is compatible with
550
+
existing host naming conventions. Name servers and resolvers must
551
+
compare labels in a case-insensitive manner (i.e., A=a), assuming ASCII
552
+
with zero parity. Non-alphabetic codes must match exactly.
553
+
554
+
555
+
556
+
Mockapetris [Page 10]
557
+
558
+
RFC 1035 Domain Implementation and Specification November 1987
559
+
560
+
561
+
3.2. RR definitions
562
+
563
+
3.2.1. Format
564
+
565
+
All RRs have the same top level format shown below:
566
+
567
+
1 1 1 1 1 1
568
+
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
569
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
570
+
| |
571
+
/ /
572
+
/ NAME /
573
+
| |
574
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
575
+
| TYPE |
576
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
577
+
| CLASS |
578
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
579
+
| TTL |
580
+
| |
581
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
582
+
| RDLENGTH |
583
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--|
584
+
/ RDATA /
585
+
/ /
586
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
587
+
588
+
589
+
where:
590
+
591
+
NAME an owner name, i.e., the name of the node to which this
592
+
resource record pertains.
593
+
594
+
TYPE two octets containing one of the RR TYPE codes.
595
+
596
+
CLASS two octets containing one of the RR CLASS codes.
597
+
598
+
TTL a 32 bit signed integer that specifies the time interval
599
+
that the resource record may be cached before the source
600
+
of the information should again be consulted. Zero
601
+
values are interpreted to mean that the RR can only be
602
+
used for the transaction in progress, and should not be
603
+
cached. For example, SOA records are always distributed
604
+
with a zero TTL to prohibit caching. Zero values can
605
+
also be used for extremely volatile data.
606
+
607
+
RDLENGTH an unsigned 16 bit integer that specifies the length in
608
+
octets of the RDATA field.
609
+
610
+
611
+
612
+
Mockapetris [Page 11]
613
+
614
+
RFC 1035 Domain Implementation and Specification November 1987
615
+
616
+
617
+
RDATA a variable length string of octets that describes the
618
+
resource. The format of this information varies
619
+
according to the TYPE and CLASS of the resource record.
620
+
621
+
3.2.2. TYPE values
622
+
623
+
TYPE fields are used in resource records. Note that these types are a
624
+
subset of QTYPEs.
625
+
626
+
TYPE value and meaning
627
+
628
+
A 1 a host address
629
+
630
+
NS 2 an authoritative name server
631
+
632
+
MD 3 a mail destination (Obsolete - use MX)
633
+
634
+
MF 4 a mail forwarder (Obsolete - use MX)
635
+
636
+
CNAME 5 the canonical name for an alias
637
+
638
+
SOA 6 marks the start of a zone of authority
639
+
640
+
MB 7 a mailbox domain name (EXPERIMENTAL)
641
+
642
+
MG 8 a mail group member (EXPERIMENTAL)
643
+
644
+
MR 9 a mail rename domain name (EXPERIMENTAL)
645
+
646
+
NULL 10 a null RR (EXPERIMENTAL)
647
+
648
+
WKS 11 a well known service description
649
+
650
+
PTR 12 a domain name pointer
651
+
652
+
HINFO 13 host information
653
+
654
+
MINFO 14 mailbox or mail list information
655
+
656
+
MX 15 mail exchange
657
+
658
+
TXT 16 text strings
659
+
660
+
3.2.3. QTYPE values
661
+
662
+
QTYPE fields appear in the question part of a query. QTYPES are a
663
+
superset of TYPEs, hence all TYPEs are valid QTYPEs. In addition, the
664
+
following QTYPEs are defined:
665
+
666
+
667
+
668
+
Mockapetris [Page 12]
669
+
670
+
RFC 1035 Domain Implementation and Specification November 1987
671
+
672
+
673
+
AXFR 252 A request for a transfer of an entire zone
674
+
675
+
MAILB 253 A request for mailbox-related records (MB, MG or MR)
676
+
677
+
MAILA 254 A request for mail agent RRs (Obsolete - see MX)
678
+
679
+
* 255 A request for all records
680
+
681
+
3.2.4. CLASS values
682
+
683
+
CLASS fields appear in resource records. The following CLASS mnemonics
684
+
and values are defined:
685
+
686
+
IN 1 the Internet
687
+
688
+
CS 2 the CSNET class (Obsolete - used only for examples in
689
+
some obsolete RFCs)
690
+
691
+
CH 3 the CHAOS class
692
+
693
+
HS 4 Hesiod [Dyer 87]
694
+
695
+
3.2.5. QCLASS values
696
+
697
+
QCLASS fields appear in the question section of a query. QCLASS values
698
+
are a superset of CLASS values; every CLASS is a valid QCLASS. In
699
+
addition to CLASS values, the following QCLASSes are defined:
700
+
701
+
* 255 any class
702
+
703
+
3.3. Standard RRs
704
+
705
+
The following RR definitions are expected to occur, at least
706
+
potentially, in all classes. In particular, NS, SOA, CNAME, and PTR
707
+
will be used in all classes, and have the same format in all classes.
708
+
Because their RDATA format is known, all domain names in the RDATA
709
+
section of these RRs may be compressed.
710
+
711
+
<domain-name> is a domain name represented as a series of labels, and
712
+
terminated by a label with zero length. <character-string> is a single
713
+
length octet followed by that number of characters. <character-string>
714
+
is treated as binary information, and can be up to 256 characters in
715
+
length (including the length octet).
716
+
717
+
718
+
719
+
720
+
721
+
722
+
723
+
724
+
Mockapetris [Page 13]
725
+
726
+
RFC 1035 Domain Implementation and Specification November 1987
727
+
728
+
729
+
3.3.1. CNAME RDATA format
730
+
731
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
732
+
/ CNAME /
733
+
/ /
734
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
735
+
736
+
where:
737
+
738
+
CNAME A <domain-name> which specifies the canonical or primary
739
+
name for the owner. The owner name is an alias.
740
+
741
+
CNAME RRs cause no additional section processing, but name servers may
742
+
choose to restart the query at the canonical name in certain cases. See
743
+
the description of name server logic in [RFC-1034] for details.
744
+
745
+
3.3.2. HINFO RDATA format
746
+
747
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
748
+
/ CPU /
749
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
750
+
/ OS /
751
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
752
+
753
+
where:
754
+
755
+
CPU A <character-string> which specifies the CPU type.
756
+
757
+
OS A <character-string> which specifies the operating
758
+
system type.
759
+
760
+
Standard values for CPU and OS can be found in [RFC-1010].
761
+
762
+
HINFO records are used to acquire general information about a host. The
763
+
main use is for protocols such as FTP that can use special procedures
764
+
when talking between machines or operating systems of the same type.
765
+
766
+
3.3.3. MB RDATA format (EXPERIMENTAL)
767
+
768
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
769
+
/ MADNAME /
770
+
/ /
771
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
772
+
773
+
where:
774
+
775
+
MADNAME A <domain-name> which specifies a host which has the
776
+
specified mailbox.
777
+
778
+
779
+
780
+
Mockapetris [Page 14]
781
+
782
+
RFC 1035 Domain Implementation and Specification November 1987
783
+
784
+
785
+
MB records cause additional section processing which looks up an A type
786
+
RRs corresponding to MADNAME.
787
+
788
+
3.3.4. MD RDATA format (Obsolete)
789
+
790
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
791
+
/ MADNAME /
792
+
/ /
793
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
794
+
795
+
where:
796
+
797
+
MADNAME A <domain-name> which specifies a host which has a mail
798
+
agent for the domain which should be able to deliver
799
+
mail for the domain.
800
+
801
+
MD records cause additional section processing which looks up an A type
802
+
record corresponding to MADNAME.
803
+
804
+
MD is obsolete. See the definition of MX and [RFC-974] for details of
805
+
the new scheme. The recommended policy for dealing with MD RRs found in
806
+
a master file is to reject them, or to convert them to MX RRs with a
807
+
preference of 0.
808
+
809
+
3.3.5. MF RDATA format (Obsolete)
810
+
811
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
812
+
/ MADNAME /
813
+
/ /
814
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
815
+
816
+
where:
817
+
818
+
MADNAME A <domain-name> which specifies a host which has a mail
819
+
agent for the domain which will accept mail for
820
+
forwarding to the domain.
821
+
822
+
MF records cause additional section processing which looks up an A type
823
+
record corresponding to MADNAME.
824
+
825
+
MF is obsolete. See the definition of MX and [RFC-974] for details ofw
826
+
the new scheme. The recommended policy for dealing with MD RRs found in
827
+
a master file is to reject them, or to convert them to MX RRs with a
828
+
preference of 10.
829
+
830
+
831
+
832
+
833
+
834
+
835
+
836
+
Mockapetris [Page 15]
837
+
838
+
RFC 1035 Domain Implementation and Specification November 1987
839
+
840
+
841
+
3.3.6. MG RDATA format (EXPERIMENTAL)
842
+
843
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
844
+
/ MGMNAME /
845
+
/ /
846
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
847
+
848
+
where:
849
+
850
+
MGMNAME A <domain-name> which specifies a mailbox which is a
851
+
member of the mail group specified by the domain name.
852
+
853
+
MG records cause no additional section processing.
854
+
855
+
3.3.7. MINFO RDATA format (EXPERIMENTAL)
856
+
857
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
858
+
/ RMAILBX /
859
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
860
+
/ EMAILBX /
861
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
862
+
863
+
where:
864
+
865
+
RMAILBX A <domain-name> which specifies a mailbox which is
866
+
responsible for the mailing list or mailbox. If this
867
+
domain name names the root, the owner of the MINFO RR is
868
+
responsible for itself. Note that many existing mailing
869
+
lists use a mailbox X-request for the RMAILBX field of
870
+
mailing list X, e.g., Msgroup-request for Msgroup. This
871
+
field provides a more general mechanism.
872
+
873
+
874
+
EMAILBX A <domain-name> which specifies a mailbox which is to
875
+
receive error messages related to the mailing list or
876
+
mailbox specified by the owner of the MINFO RR (similar
877
+
to the ERRORS-TO: field which has been proposed). If
878
+
this domain name names the root, errors should be
879
+
returned to the sender of the message.
880
+
881
+
MINFO records cause no additional section processing. Although these
882
+
records can be associated with a simple mailbox, they are usually used
883
+
with a mailing list.
884
+
885
+
886
+
887
+
888
+
889
+
890
+
891
+
892
+
Mockapetris [Page 16]
893
+
894
+
RFC 1035 Domain Implementation and Specification November 1987
895
+
896
+
897
+
3.3.8. MR RDATA format (EXPERIMENTAL)
898
+
899
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
900
+
/ NEWNAME /
901
+
/ /
902
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
903
+
904
+
where:
905
+
906
+
NEWNAME A <domain-name> which specifies a mailbox which is the
907
+
proper rename of the specified mailbox.
908
+
909
+
MR records cause no additional section processing. The main use for MR
910
+
is as a forwarding entry for a user who has moved to a different
911
+
mailbox.
912
+
913
+
3.3.9. MX RDATA format
914
+
915
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
916
+
| PREFERENCE |
917
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
918
+
/ EXCHANGE /
919
+
/ /
920
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
921
+
922
+
where:
923
+
924
+
PREFERENCE A 16 bit integer which specifies the preference given to
925
+
this RR among others at the same owner. Lower values
926
+
are preferred.
927
+
928
+
EXCHANGE A <domain-name> which specifies a host willing to act as
929
+
a mail exchange for the owner name.
930
+
931
+
MX records cause type A additional section processing for the host
932
+
specified by EXCHANGE. The use of MX RRs is explained in detail in
933
+
[RFC-974].
934
+
935
+
3.3.10. NULL RDATA format (EXPERIMENTAL)
936
+
937
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
938
+
/ <anything> /
939
+
/ /
940
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
941
+
942
+
Anything at all may be in the RDATA field so long as it is 65535 octets
943
+
or less.
944
+
945
+
946
+
947
+
948
+
Mockapetris [Page 17]
949
+
950
+
RFC 1035 Domain Implementation and Specification November 1987
951
+
952
+
953
+
NULL records cause no additional section processing. NULL RRs are not
954
+
allowed in master files. NULLs are used as placeholders in some
955
+
experimental extensions of the DNS.
956
+
957
+
3.3.11. NS RDATA format
958
+
959
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
960
+
/ NSDNAME /
961
+
/ /
962
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
963
+
964
+
where:
965
+
966
+
NSDNAME A <domain-name> which specifies a host which should be
967
+
authoritative for the specified class and domain.
968
+
969
+
NS records cause both the usual additional section processing to locate
970
+
a type A record, and, when used in a referral, a special search of the
971
+
zone in which they reside for glue information.
972
+
973
+
The NS RR states that the named host should be expected to have a zone
974
+
starting at owner name of the specified class. Note that the class may
975
+
not indicate the protocol family which should be used to communicate
976
+
with the host, although it is typically a strong hint. For example,
977
+
hosts which are name servers for either Internet (IN) or Hesiod (HS)
978
+
class information are normally queried using IN class protocols.
979
+
980
+
3.3.12. PTR RDATA format
981
+
982
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
983
+
/ PTRDNAME /
984
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
985
+
986
+
where:
987
+
988
+
PTRDNAME A <domain-name> which points to some location in the
989
+
domain name space.
990
+
991
+
PTR records cause no additional section processing. These RRs are used
992
+
in special domains to point to some other location in the domain space.
993
+
These records are simple data, and don't imply any special processing
994
+
similar to that performed by CNAME, which identifies aliases. See the
995
+
description of the IN-ADDR.ARPA domain for an example.
996
+
997
+
998
+
999
+
1000
+
1001
+
1002
+
1003
+
1004
+
Mockapetris [Page 18]
1005
+
1006
+
RFC 1035 Domain Implementation and Specification November 1987
1007
+
1008
+
1009
+
3.3.13. SOA RDATA format
1010
+
1011
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1012
+
/ MNAME /
1013
+
/ /
1014
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1015
+
/ RNAME /
1016
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1017
+
| SERIAL |
1018
+
| |
1019
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1020
+
| REFRESH |
1021
+
| |
1022
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1023
+
| RETRY |
1024
+
| |
1025
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1026
+
| EXPIRE |
1027
+
| |
1028
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1029
+
| MINIMUM |
1030
+
| |
1031
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1032
+
1033
+
where:
1034
+
1035
+
MNAME The <domain-name> of the name server that was the
1036
+
original or primary source of data for this zone.
1037
+
1038
+
RNAME A <domain-name> which specifies the mailbox of the
1039
+
person responsible for this zone.
1040
+
1041
+
SERIAL The unsigned 32 bit version number of the original copy
1042
+
of the zone. Zone transfers preserve this value. This
1043
+
value wraps and should be compared using sequence space
1044
+
arithmetic.
1045
+
1046
+
REFRESH A 32 bit time interval before the zone should be
1047
+
refreshed.
1048
+
1049
+
RETRY A 32 bit time interval that should elapse before a
1050
+
failed refresh should be retried.
1051
+
1052
+
EXPIRE A 32 bit time value that specifies the upper limit on
1053
+
the time interval that can elapse before the zone is no
1054
+
longer authoritative.
1055
+
1056
+
1057
+
1058
+
1059
+
1060
+
Mockapetris [Page 19]
1061
+
1062
+
RFC 1035 Domain Implementation and Specification November 1987
1063
+
1064
+
1065
+
MINIMUM The unsigned 32 bit minimum TTL field that should be
1066
+
exported with any RR from this zone.
1067
+
1068
+
SOA records cause no additional section processing.
1069
+
1070
+
All times are in units of seconds.
1071
+
1072
+
Most of these fields are pertinent only for name server maintenance
1073
+
operations. However, MINIMUM is used in all query operations that
1074
+
retrieve RRs from a zone. Whenever a RR is sent in a response to a
1075
+
query, the TTL field is set to the maximum of the TTL field from the RR
1076
+
and the MINIMUM field in the appropriate SOA. Thus MINIMUM is a lower
1077
+
bound on the TTL field for all RRs in a zone. Note that this use of
1078
+
MINIMUM should occur when the RRs are copied into the response and not
1079
+
when the zone is loaded from a master file or via a zone transfer. The
1080
+
reason for this provison is to allow future dynamic update facilities to
1081
+
change the SOA RR with known semantics.
1082
+
1083
+
1084
+
3.3.14. TXT RDATA format
1085
+
1086
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1087
+
/ TXT-DATA /
1088
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1089
+
1090
+
where:
1091
+
1092
+
TXT-DATA One or more <character-string>s.
1093
+
1094
+
TXT RRs are used to hold descriptive text. The semantics of the text
1095
+
depends on the domain where it is found.
1096
+
1097
+
3.4. Internet specific RRs
1098
+
1099
+
3.4.1. A RDATA format
1100
+
1101
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1102
+
| ADDRESS |
1103
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1104
+
1105
+
where:
1106
+
1107
+
ADDRESS A 32 bit Internet address.
1108
+
1109
+
Hosts that have multiple Internet addresses will have multiple A
1110
+
records.
1111
+
1112
+
1113
+
1114
+
1115
+
1116
+
Mockapetris [Page 20]
1117
+
1118
+
RFC 1035 Domain Implementation and Specification November 1987
1119
+
1120
+
1121
+
A records cause no additional section processing. The RDATA section of
1122
+
an A line in a master file is an Internet address expressed as four
1123
+
decimal numbers separated by dots without any imbedded spaces (e.g.,
1124
+
"10.2.0.52" or "192.0.5.6").
1125
+
1126
+
3.4.2. WKS RDATA format
1127
+
1128
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1129
+
| ADDRESS |
1130
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1131
+
| PROTOCOL | |
1132
+
+--+--+--+--+--+--+--+--+ |
1133
+
| |
1134
+
/ <BIT MAP> /
1135
+
/ /
1136
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1137
+
1138
+
where:
1139
+
1140
+
ADDRESS An 32 bit Internet address
1141
+
1142
+
PROTOCOL An 8 bit IP protocol number
1143
+
1144
+
<BIT MAP> A variable length bit map. The bit map must be a
1145
+
multiple of 8 bits long.
1146
+
1147
+
The WKS record is used to describe the well known services supported by
1148
+
a particular protocol on a particular internet address. The PROTOCOL
1149
+
field specifies an IP protocol number, and the bit map has one bit per
1150
+
port of the specified protocol. The first bit corresponds to port 0,
1151
+
the second to port 1, etc. If the bit map does not include a bit for a
1152
+
protocol of interest, that bit is assumed zero. The appropriate values
1153
+
and mnemonics for ports and protocols are specified in [RFC-1010].
1154
+
1155
+
For example, if PROTOCOL=TCP (6), the 26th bit corresponds to TCP port
1156
+
25 (SMTP). If this bit is set, a SMTP server should be listening on TCP
1157
+
port 25; if zero, SMTP service is not supported on the specified
1158
+
address.
1159
+
1160
+
The purpose of WKS RRs is to provide availability information for
1161
+
servers for TCP and UDP. If a server supports both TCP and UDP, or has
1162
+
multiple Internet addresses, then multiple WKS RRs are used.
1163
+
1164
+
WKS RRs cause no additional section processing.
1165
+
1166
+
In master files, both ports and protocols are expressed using mnemonics
1167
+
or decimal numbers.
1168
+
1169
+
1170
+
1171
+
1172
+
Mockapetris [Page 21]
1173
+
1174
+
RFC 1035 Domain Implementation and Specification November 1987
1175
+
1176
+
1177
+
3.5. IN-ADDR.ARPA domain
1178
+
1179
+
The Internet uses a special domain to support gateway location and
1180
+
Internet address to host mapping. Other classes may employ a similar
1181
+
strategy in other domains. The intent of this domain is to provide a
1182
+
guaranteed method to perform host address to host name mapping, and to
1183
+
facilitate queries to locate all gateways on a particular network in the
1184
+
Internet.
1185
+
1186
+
Note that both of these services are similar to functions that could be
1187
+
performed by inverse queries; the difference is that this part of the
1188
+
domain name space is structured according to address, and hence can
1189
+
guarantee that the appropriate data can be located without an exhaustive
1190
+
search of the domain space.
1191
+
1192
+
The domain begins at IN-ADDR.ARPA and has a substructure which follows
1193
+
the Internet addressing structure.
1194
+
1195
+
Domain names in the IN-ADDR.ARPA domain are defined to have up to four
1196
+
labels in addition to the IN-ADDR.ARPA suffix. Each label represents
1197
+
one octet of an Internet address, and is expressed as a character string
1198
+
for a decimal value in the range 0-255 (with leading zeros omitted
1199
+
except in the case of a zero octet which is represented by a single
1200
+
zero).
1201
+
1202
+
Host addresses are represented by domain names that have all four labels
1203
+
specified. Thus data for Internet address 10.2.0.52 is located at
1204
+
domain name 52.0.2.10.IN-ADDR.ARPA. The reversal, though awkward to
1205
+
read, allows zones to be delegated which are exactly one network of
1206
+
address space. For example, 10.IN-ADDR.ARPA can be a zone containing
1207
+
data for the ARPANET, while 26.IN-ADDR.ARPA can be a separate zone for
1208
+
MILNET. Address nodes are used to hold pointers to primary host names
1209
+
in the normal domain space.
1210
+
1211
+
Network numbers correspond to some non-terminal nodes at various depths
1212
+
in the IN-ADDR.ARPA domain, since Internet network numbers are either 1,
1213
+
2, or 3 octets. Network nodes are used to hold pointers to the primary
1214
+
host names of gateways attached to that network. Since a gateway is, by
1215
+
definition, on more than one network, it will typically have two or more
1216
+
network nodes which point at it. Gateways will also have host level
1217
+
pointers at their fully qualified addresses.
1218
+
1219
+
Both the gateway pointers at network nodes and the normal host pointers
1220
+
at full address nodes use the PTR RR to point back to the primary domain
1221
+
names of the corresponding hosts.
1222
+
1223
+
For example, the IN-ADDR.ARPA domain will contain information about the
1224
+
ISI gateway between net 10 and 26, an MIT gateway from net 10 to MIT's
1225
+
1226
+
1227
+
1228
+
Mockapetris [Page 22]
1229
+
1230
+
RFC 1035 Domain Implementation and Specification November 1987
1231
+
1232
+
1233
+
net 18, and hosts A.ISI.EDU and MULTICS.MIT.EDU. Assuming that ISI
1234
+
gateway has addresses 10.2.0.22 and 26.0.0.103, and a name MILNET-
1235
+
GW.ISI.EDU, and the MIT gateway has addresses 10.0.0.77 and 18.10.0.4
1236
+
and a name GW.LCS.MIT.EDU, the domain database would contain:
1237
+
1238
+
10.IN-ADDR.ARPA. PTR MILNET-GW.ISI.EDU.
1239
+
10.IN-ADDR.ARPA. PTR GW.LCS.MIT.EDU.
1240
+
18.IN-ADDR.ARPA. PTR GW.LCS.MIT.EDU.
1241
+
26.IN-ADDR.ARPA. PTR MILNET-GW.ISI.EDU.
1242
+
22.0.2.10.IN-ADDR.ARPA. PTR MILNET-GW.ISI.EDU.
1243
+
103.0.0.26.IN-ADDR.ARPA. PTR MILNET-GW.ISI.EDU.
1244
+
77.0.0.10.IN-ADDR.ARPA. PTR GW.LCS.MIT.EDU.
1245
+
4.0.10.18.IN-ADDR.ARPA. PTR GW.LCS.MIT.EDU.
1246
+
103.0.3.26.IN-ADDR.ARPA. PTR A.ISI.EDU.
1247
+
6.0.0.10.IN-ADDR.ARPA. PTR MULTICS.MIT.EDU.
1248
+
1249
+
Thus a program which wanted to locate gateways on net 10 would originate
1250
+
a query of the form QTYPE=PTR, QCLASS=IN, QNAME=10.IN-ADDR.ARPA. It
1251
+
would receive two RRs in response:
1252
+
1253
+
10.IN-ADDR.ARPA. PTR MILNET-GW.ISI.EDU.
1254
+
10.IN-ADDR.ARPA. PTR GW.LCS.MIT.EDU.
1255
+
1256
+
The program could then originate QTYPE=A, QCLASS=IN queries for MILNET-
1257
+
GW.ISI.EDU. and GW.LCS.MIT.EDU. to discover the Internet addresses of
1258
+
these gateways.
1259
+
1260
+
A resolver which wanted to find the host name corresponding to Internet
1261
+
host address 10.0.0.6 would pursue a query of the form QTYPE=PTR,
1262
+
QCLASS=IN, QNAME=6.0.0.10.IN-ADDR.ARPA, and would receive:
1263
+
1264
+
6.0.0.10.IN-ADDR.ARPA. PTR MULTICS.MIT.EDU.
1265
+
1266
+
Several cautions apply to the use of these services:
1267
+
- Since the IN-ADDR.ARPA special domain and the normal domain
1268
+
for a particular host or gateway will be in different zones,
1269
+
the possibility exists that that the data may be inconsistent.
1270
+
1271
+
- Gateways will often have two names in separate domains, only
1272
+
one of which can be primary.
1273
+
1274
+
- Systems that use the domain database to initialize their
1275
+
routing tables must start with enough gateway information to
1276
+
guarantee that they can access the appropriate name server.
1277
+
1278
+
- The gateway data only reflects the existence of a gateway in a
1279
+
manner equivalent to the current HOSTS.TXT file. It doesn't
1280
+
replace the dynamic availability information from GGP or EGP.
1281
+
1282
+
1283
+
1284
+
Mockapetris [Page 23]
1285
+
1286
+
RFC 1035 Domain Implementation and Specification November 1987
1287
+
1288
+
1289
+
3.6. Defining new types, classes, and special namespaces
1290
+
1291
+
The previously defined types and classes are the ones in use as of the
1292
+
date of this memo. New definitions should be expected. This section
1293
+
makes some recommendations to designers considering additions to the
1294
+
existing facilities. The mailing list NAMEDROPPERS@SRI-NIC.ARPA is the
1295
+
forum where general discussion of design issues takes place.
1296
+
1297
+
In general, a new type is appropriate when new information is to be
1298
+
added to the database about an existing object, or we need new data
1299
+
formats for some totally new object. Designers should attempt to define
1300
+
types and their RDATA formats that are generally applicable to all
1301
+
classes, and which avoid duplication of information. New classes are
1302
+
appropriate when the DNS is to be used for a new protocol, etc which
1303
+
requires new class-specific data formats, or when a copy of the existing
1304
+
name space is desired, but a separate management domain is necessary.
1305
+
1306
+
New types and classes need mnemonics for master files; the format of the
1307
+
master files requires that the mnemonics for type and class be disjoint.
1308
+
1309
+
TYPE and CLASS values must be a proper subset of QTYPEs and QCLASSes
1310
+
respectively.
1311
+
1312
+
The present system uses multiple RRs to represent multiple values of a
1313
+
type rather than storing multiple values in the RDATA section of a
1314
+
single RR. This is less efficient for most applications, but does keep
1315
+
RRs shorter. The multiple RRs assumption is incorporated in some
1316
+
experimental work on dynamic update methods.
1317
+
1318
+
The present system attempts to minimize the duplication of data in the
1319
+
database in order to insure consistency. Thus, in order to find the
1320
+
address of the host for a mail exchange, you map the mail domain name to
1321
+
a host name, then the host name to addresses, rather than a direct
1322
+
mapping to host address. This approach is preferred because it avoids
1323
+
the opportunity for inconsistency.
1324
+
1325
+
In defining a new type of data, multiple RR types should not be used to
1326
+
create an ordering between entries or express different formats for
1327
+
equivalent bindings, instead this information should be carried in the
1328
+
body of the RR and a single type used. This policy avoids problems with
1329
+
caching multiple types and defining QTYPEs to match multiple types.
1330
+
1331
+
For example, the original form of mail exchange binding used two RR
1332
+
types one to represent a "closer" exchange (MD) and one to represent a
1333
+
"less close" exchange (MF). The difficulty is that the presence of one
1334
+
RR type in a cache doesn't convey any information about the other
1335
+
because the query which acquired the cached information might have used
1336
+
a QTYPE of MF, MD, or MAILA (which matched both). The redesigned
1337
+
1338
+
1339
+
1340
+
Mockapetris [Page 24]
1341
+
1342
+
RFC 1035 Domain Implementation and Specification November 1987
1343
+
1344
+
1345
+
service used a single type (MX) with a "preference" value in the RDATA
1346
+
section which can order different RRs. However, if any MX RRs are found
1347
+
in the cache, then all should be there.
1348
+
1349
+
4. MESSAGES
1350
+
1351
+
4.1. Format
1352
+
1353
+
All communications inside of the domain protocol are carried in a single
1354
+
format called a message. The top level format of message is divided
1355
+
into 5 sections (some of which are empty in certain cases) shown below:
1356
+
1357
+
+---------------------+
1358
+
| Header |
1359
+
+---------------------+
1360
+
| Question | the question for the name server
1361
+
+---------------------+
1362
+
| Answer | RRs answering the question
1363
+
+---------------------+
1364
+
| Authority | RRs pointing toward an authority
1365
+
+---------------------+
1366
+
| Additional | RRs holding additional information
1367
+
+---------------------+
1368
+
1369
+
The header section is always present. The header includes fields that
1370
+
specify which of the remaining sections are present, and also specify
1371
+
whether the message is a query or a response, a standard query or some
1372
+
other opcode, etc.
1373
+
1374
+
The names of the sections after the header are derived from their use in
1375
+
standard queries. The question section contains fields that describe a
1376
+
question to a name server. These fields are a query type (QTYPE), a
1377
+
query class (QCLASS), and a query domain name (QNAME). The last three
1378
+
sections have the same format: a possibly empty list of concatenated
1379
+
resource records (RRs). The answer section contains RRs that answer the
1380
+
question; the authority section contains RRs that point toward an
1381
+
authoritative name server; the additional records section contains RRs
1382
+
which relate to the query, but are not strictly answers for the
1383
+
question.
1384
+
1385
+
1386
+
1387
+
1388
+
1389
+
1390
+
1391
+
1392
+
1393
+
1394
+
1395
+
1396
+
Mockapetris [Page 25]
1397
+
1398
+
RFC 1035 Domain Implementation and Specification November 1987
1399
+
1400
+
1401
+
4.1.1. Header section format
1402
+
1403
+
The header contains the following fields:
1404
+
1405
+
1 1 1 1 1 1
1406
+
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
1407
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1408
+
| ID |
1409
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1410
+
|QR| Opcode |AA|TC|RD|RA| Z | RCODE |
1411
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1412
+
| QDCOUNT |
1413
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1414
+
| ANCOUNT |
1415
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1416
+
| NSCOUNT |
1417
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1418
+
| ARCOUNT |
1419
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1420
+
1421
+
where:
1422
+
1423
+
ID A 16 bit identifier assigned by the program that
1424
+
generates any kind of query. This identifier is copied
1425
+
the corresponding reply and can be used by the requester
1426
+
to match up replies to outstanding queries.
1427
+
1428
+
QR A one bit field that specifies whether this message is a
1429
+
query (0), or a response (1).
1430
+
1431
+
OPCODE A four bit field that specifies kind of query in this
1432
+
message. This value is set by the originator of a query
1433
+
and copied into the response. The values are:
1434
+
1435
+
0 a standard query (QUERY)
1436
+
1437
+
1 an inverse query (IQUERY)
1438
+
1439
+
2 a server status request (STATUS)
1440
+
1441
+
3-15 reserved for future use
1442
+
1443
+
AA Authoritative Answer - this bit is valid in responses,
1444
+
and specifies that the responding name server is an
1445
+
authority for the domain name in question section.
1446
+
1447
+
Note that the contents of the answer section may have
1448
+
multiple owner names because of aliases. The AA bit
1449
+
1450
+
1451
+
1452
+
Mockapetris [Page 26]
1453
+
1454
+
RFC 1035 Domain Implementation and Specification November 1987
1455
+
1456
+
1457
+
corresponds to the name which matches the query name, or
1458
+
the first owner name in the answer section.
1459
+
1460
+
TC TrunCation - specifies that this message was truncated
1461
+
due to length greater than that permitted on the
1462
+
transmission channel.
1463
+
1464
+
RD Recursion Desired - this bit may be set in a query and
1465
+
is copied into the response. If RD is set, it directs
1466
+
the name server to pursue the query recursively.
1467
+
Recursive query support is optional.
1468
+
1469
+
RA Recursion Available - this be is set or cleared in a
1470
+
response, and denotes whether recursive query support is
1471
+
available in the name server.
1472
+
1473
+
Z Reserved for future use. Must be zero in all queries
1474
+
and responses.
1475
+
1476
+
RCODE Response code - this 4 bit field is set as part of
1477
+
responses. The values have the following
1478
+
interpretation:
1479
+
1480
+
0 No error condition
1481
+
1482
+
1 Format error - The name server was
1483
+
unable to interpret the query.
1484
+
1485
+
2 Server failure - The name server was
1486
+
unable to process this query due to a
1487
+
problem with the name server.
1488
+
1489
+
3 Name Error - Meaningful only for
1490
+
responses from an authoritative name
1491
+
server, this code signifies that the
1492
+
domain name referenced in the query does
1493
+
not exist.
1494
+
1495
+
4 Not Implemented - The name server does
1496
+
not support the requested kind of query.
1497
+
1498
+
5 Refused - The name server refuses to
1499
+
perform the specified operation for
1500
+
policy reasons. For example, a name
1501
+
server may not wish to provide the
1502
+
information to the particular requester,
1503
+
or a name server may not wish to perform
1504
+
a particular operation (e.g., zone
1505
+
1506
+
1507
+
1508
+
Mockapetris [Page 27]
1509
+
1510
+
RFC 1035 Domain Implementation and Specification November 1987
1511
+
1512
+
1513
+
transfer) for particular data.
1514
+
1515
+
6-15 Reserved for future use.
1516
+
1517
+
QDCOUNT an unsigned 16 bit integer specifying the number of
1518
+
entries in the question section.
1519
+
1520
+
ANCOUNT an unsigned 16 bit integer specifying the number of
1521
+
resource records in the answer section.
1522
+
1523
+
NSCOUNT an unsigned 16 bit integer specifying the number of name
1524
+
server resource records in the authority records
1525
+
section.
1526
+
1527
+
ARCOUNT an unsigned 16 bit integer specifying the number of
1528
+
resource records in the additional records section.
1529
+
1530
+
4.1.2. Question section format
1531
+
1532
+
The question section is used to carry the "question" in most queries,
1533
+
i.e., the parameters that define what is being asked. The section
1534
+
contains QDCOUNT (usually 1) entries, each of the following format:
1535
+
1536
+
1 1 1 1 1 1
1537
+
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
1538
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1539
+
| |
1540
+
/ QNAME /
1541
+
/ /
1542
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1543
+
| QTYPE |
1544
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1545
+
| QCLASS |
1546
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1547
+
1548
+
where:
1549
+
1550
+
QNAME a domain name represented as a sequence of labels, where
1551
+
each label consists of a length octet followed by that
1552
+
number of octets. The domain name terminates with the
1553
+
zero length octet for the null label of the root. Note
1554
+
that this field may be an odd number of octets; no
1555
+
padding is used.
1556
+
1557
+
QTYPE a two octet code which specifies the type of the query.
1558
+
The values for this field include all codes valid for a
1559
+
TYPE field, together with some more general codes which
1560
+
can match more than one type of RR.
1561
+
1562
+
1563
+
1564
+
Mockapetris [Page 28]
1565
+
1566
+
RFC 1035 Domain Implementation and Specification November 1987
1567
+
1568
+
1569
+
QCLASS a two octet code that specifies the class of the query.
1570
+
For example, the QCLASS field is IN for the Internet.
1571
+
1572
+
4.1.3. Resource record format
1573
+
1574
+
The answer, authority, and additional sections all share the same
1575
+
format: a variable number of resource records, where the number of
1576
+
records is specified in the corresponding count field in the header.
1577
+
Each resource record has the following format:
1578
+
1 1 1 1 1 1
1579
+
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
1580
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1581
+
| |
1582
+
/ /
1583
+
/ NAME /
1584
+
| |
1585
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1586
+
| TYPE |
1587
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1588
+
| CLASS |
1589
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1590
+
| TTL |
1591
+
| |
1592
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1593
+
| RDLENGTH |
1594
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--|
1595
+
/ RDATA /
1596
+
/ /
1597
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1598
+
1599
+
where:
1600
+
1601
+
NAME a domain name to which this resource record pertains.
1602
+
1603
+
TYPE two octets containing one of the RR type codes. This
1604
+
field specifies the meaning of the data in the RDATA
1605
+
field.
1606
+
1607
+
CLASS two octets which specify the class of the data in the
1608
+
RDATA field.
1609
+
1610
+
TTL a 32 bit unsigned integer that specifies the time
1611
+
interval (in seconds) that the resource record may be
1612
+
cached before it should be discarded. Zero values are
1613
+
interpreted to mean that the RR can only be used for the
1614
+
transaction in progress, and should not be cached.
1615
+
1616
+
1617
+
1618
+
1619
+
1620
+
Mockapetris [Page 29]
1621
+
1622
+
RFC 1035 Domain Implementation and Specification November 1987
1623
+
1624
+
1625
+
RDLENGTH an unsigned 16 bit integer that specifies the length in
1626
+
octets of the RDATA field.
1627
+
1628
+
RDATA a variable length string of octets that describes the
1629
+
resource. The format of this information varies
1630
+
according to the TYPE and CLASS of the resource record.
1631
+
For example, the if the TYPE is A and the CLASS is IN,
1632
+
the RDATA field is a 4 octet ARPA Internet address.
1633
+
1634
+
4.1.4. Message compression
1635
+
1636
+
In order to reduce the size of messages, the domain system utilizes a
1637
+
compression scheme which eliminates the repetition of domain names in a
1638
+
message. In this scheme, an entire domain name or a list of labels at
1639
+
the end of a domain name is replaced with a pointer to a prior occurance
1640
+
of the same name.
1641
+
1642
+
The pointer takes the form of a two octet sequence:
1643
+
1644
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1645
+
| 1 1| OFFSET |
1646
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1647
+
1648
+
The first two bits are ones. This allows a pointer to be distinguished
1649
+
from a label, since the label must begin with two zero bits because
1650
+
labels are restricted to 63 octets or less. (The 10 and 01 combinations
1651
+
are reserved for future use.) The OFFSET field specifies an offset from
1652
+
the start of the message (i.e., the first octet of the ID field in the
1653
+
domain header). A zero offset specifies the first byte of the ID field,
1654
+
etc.
1655
+
1656
+
The compression scheme allows a domain name in a message to be
1657
+
represented as either:
1658
+
1659
+
- a sequence of labels ending in a zero octet
1660
+
1661
+
- a pointer
1662
+
1663
+
- a sequence of labels ending with a pointer
1664
+
1665
+
Pointers can only be used for occurances of a domain name where the
1666
+
format is not class specific. If this were not the case, a name server
1667
+
or resolver would be required to know the format of all RRs it handled.
1668
+
As yet, there are no such cases, but they may occur in future RDATA
1669
+
formats.
1670
+
1671
+
If a domain name is contained in a part of the message subject to a
1672
+
length field (such as the RDATA section of an RR), and compression is
1673
+
1674
+
1675
+
1676
+
Mockapetris [Page 30]
1677
+
1678
+
RFC 1035 Domain Implementation and Specification November 1987
1679
+
1680
+
1681
+
used, the length of the compressed name is used in the length
1682
+
calculation, rather than the length of the expanded name.
1683
+
1684
+
Programs are free to avoid using pointers in messages they generate,
1685
+
although this will reduce datagram capacity, and may cause truncation.
1686
+
However all programs are required to understand arriving messages that
1687
+
contain pointers.
1688
+
1689
+
For example, a datagram might need to use the domain names F.ISI.ARPA,
1690
+
FOO.F.ISI.ARPA, ARPA, and the root. Ignoring the other fields of the
1691
+
message, these domain names might be represented as:
1692
+
1693
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1694
+
20 | 1 | F |
1695
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1696
+
22 | 3 | I |
1697
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1698
+
24 | S | I |
1699
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1700
+
26 | 4 | A |
1701
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1702
+
28 | R | P |
1703
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1704
+
30 | A | 0 |
1705
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1706
+
1707
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1708
+
40 | 3 | F |
1709
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1710
+
42 | O | O |
1711
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1712
+
44 | 1 1| 20 |
1713
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1714
+
1715
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1716
+
64 | 1 1| 26 |
1717
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1718
+
1719
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1720
+
92 | 0 | |
1721
+
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1722
+
1723
+
The domain name for F.ISI.ARPA is shown at offset 20. The domain name
1724
+
FOO.F.ISI.ARPA is shown at offset 40; this definition uses a pointer to
1725
+
concatenate a label for FOO to the previously defined F.ISI.ARPA. The
1726
+
domain name ARPA is defined at offset 64 using a pointer to the ARPA
1727
+
component of the name F.ISI.ARPA at 20; note that this pointer relies on
1728
+
ARPA being the last label in the string at 20. The root domain name is
1729
+
1730
+
1731
+
1732
+
Mockapetris [Page 31]
1733
+
1734
+
RFC 1035 Domain Implementation and Specification November 1987
1735
+
1736
+
1737
+
defined by a single octet of zeros at 92; the root domain name has no
1738
+
labels.
1739
+
1740
+
4.2. Transport
1741
+
1742
+
The DNS assumes that messages will be transmitted as datagrams or in a
1743
+
byte stream carried by a virtual circuit. While virtual circuits can be
1744
+
used for any DNS activity, datagrams are preferred for queries due to
1745
+
their lower overhead and better performance. Zone refresh activities
1746
+
must use virtual circuits because of the need for reliable transfer.
1747
+
1748
+
The Internet supports name server access using TCP [RFC-793] on server
1749
+
port 53 (decimal) as well as datagram access using UDP [RFC-768] on UDP
1750
+
port 53 (decimal).
1751
+
1752
+
4.2.1. UDP usage
1753
+
1754
+
Messages sent using UDP user server port 53 (decimal).
1755
+
1756
+
Messages carried by UDP are restricted to 512 bytes (not counting the IP
1757
+
or UDP headers). Longer messages are truncated and the TC bit is set in
1758
+
the header.
1759
+
1760
+
UDP is not acceptable for zone transfers, but is the recommended method
1761
+
for standard queries in the Internet. Queries sent using UDP may be
1762
+
lost, and hence a retransmission strategy is required. Queries or their
1763
+
responses may be reordered by the network, or by processing in name
1764
+
servers, so resolvers should not depend on them being returned in order.
1765
+
1766
+
The optimal UDP retransmission policy will vary with performance of the
1767
+
Internet and the needs of the client, but the following are recommended:
1768
+
1769
+
- The client should try other servers and server addresses
1770
+
before repeating a query to a specific address of a server.
1771
+
1772
+
- The retransmission interval should be based on prior
1773
+
statistics if possible. Too aggressive retransmission can
1774
+
easily slow responses for the community at large. Depending
1775
+
on how well connected the client is to its expected servers,
1776
+
the minimum retransmission interval should be 2-5 seconds.
1777
+
1778
+
More suggestions on server selection and retransmission policy can be
1779
+
found in the resolver section of this memo.
1780
+
1781
+
4.2.2. TCP usage
1782
+
1783
+
Messages sent over TCP connections use server port 53 (decimal). The
1784
+
message is prefixed with a two byte length field which gives the message
1785
+
1786
+
1787
+
1788
+
Mockapetris [Page 32]
1789
+
1790
+
RFC 1035 Domain Implementation and Specification November 1987
1791
+
1792
+
1793
+
length, excluding the two byte length field. This length field allows
1794
+
the low-level processing to assemble a complete message before beginning
1795
+
to parse it.
1796
+
1797
+
Several connection management policies are recommended:
1798
+
1799
+
- The server should not block other activities waiting for TCP
1800
+
data.
1801
+
1802
+
- The server should support multiple connections.
1803
+
1804
+
- The server should assume that the client will initiate
1805
+
connection closing, and should delay closing its end of the
1806
+
connection until all outstanding client requests have been
1807
+
satisfied.
1808
+
1809
+
- If the server needs to close a dormant connection to reclaim
1810
+
resources, it should wait until the connection has been idle
1811
+
for a period on the order of two minutes. In particular, the
1812
+
server should allow the SOA and AXFR request sequence (which
1813
+
begins a refresh operation) to be made on a single connection.
1814
+
Since the server would be unable to answer queries anyway, a
1815
+
unilateral close or reset may be used instead of a graceful
1816
+
close.
1817
+
1818
+
5. MASTER FILES
1819
+
1820
+
Master files are text files that contain RRs in text form. Since the
1821
+
contents of a zone can be expressed in the form of a list of RRs a
1822
+
master file is most often used to define a zone, though it can be used
1823
+
to list a cache's contents. Hence, this section first discusses the
1824
+
format of RRs in a master file, and then the special considerations when
1825
+
a master file is used to create a zone in some name server.
1826
+
1827
+
5.1. Format
1828
+
1829
+
The format of these files is a sequence of entries. Entries are
1830
+
predominantly line-oriented, though parentheses can be used to continue
1831
+
a list of items across a line boundary, and text literals can contain
1832
+
CRLF within the text. Any combination of tabs and spaces act as a
1833
+
delimiter between the separate items that make up an entry. The end of
1834
+
any line in the master file can end with a comment. The comment starts
1835
+
with a ";" (semicolon).
1836
+
1837
+
The following entries are defined:
1838
+
1839
+
<blank>[<comment>]
1840
+
1841
+
1842
+
1843
+
1844
+
Mockapetris [Page 33]
1845
+
1846
+
RFC 1035 Domain Implementation and Specification November 1987
1847
+
1848
+
1849
+
$ORIGIN <domain-name> [<comment>]
1850
+
1851
+
$INCLUDE <file-name> [<domain-name>] [<comment>]
1852
+
1853
+
<domain-name><rr> [<comment>]
1854
+
1855
+
<blank><rr> [<comment>]
1856
+
1857
+
Blank lines, with or without comments, are allowed anywhere in the file.
1858
+
1859
+
Two control entries are defined: $ORIGIN and $INCLUDE. $ORIGIN is
1860
+
followed by a domain name, and resets the current origin for relative
1861
+
domain names to the stated name. $INCLUDE inserts the named file into
1862
+
the current file, and may optionally specify a domain name that sets the
1863
+
relative domain name origin for the included file. $INCLUDE may also
1864
+
have a comment. Note that a $INCLUDE entry never changes the relative
1865
+
origin of the parent file, regardless of changes to the relative origin
1866
+
made within the included file.
1867
+
1868
+
The last two forms represent RRs. If an entry for an RR begins with a
1869
+
blank, then the RR is assumed to be owned by the last stated owner. If
1870
+
an RR entry begins with a <domain-name>, then the owner name is reset.
1871
+
1872
+
<rr> contents take one of the following forms:
1873
+
1874
+
[<TTL>] [<class>] <type> <RDATA>
1875
+
1876
+
[<class>] [<TTL>] <type> <RDATA>
1877
+
1878
+
The RR begins with optional TTL and class fields, followed by a type and
1879
+
RDATA field appropriate to the type and class. Class and type use the
1880
+
standard mnemonics, TTL is a decimal integer. Omitted class and TTL
1881
+
values are default to the last explicitly stated values. Since type and
1882
+
class mnemonics are disjoint, the parse is unique. (Note that this
1883
+
order is different from the order used in examples and the order used in
1884
+
the actual RRs; the given order allows easier parsing and defaulting.)
1885
+
1886
+
<domain-name>s make up a large share of the data in the master file.
1887
+
The labels in the domain name are expressed as character strings and
1888
+
separated by dots. Quoting conventions allow arbitrary characters to be
1889
+
stored in domain names. Domain names that end in a dot are called
1890
+
absolute, and are taken as complete. Domain names which do not end in a
1891
+
dot are called relative; the actual domain name is the concatenation of
1892
+
the relative part with an origin specified in a $ORIGIN, $INCLUDE, or as
1893
+
an argument to the master file loading routine. A relative name is an
1894
+
error when no origin is available.
1895
+
1896
+
1897
+
1898
+
1899
+
1900
+
Mockapetris [Page 34]
1901
+
1902
+
RFC 1035 Domain Implementation and Specification November 1987
1903
+
1904
+
1905
+
<character-string> is expressed in one or two ways: as a contiguous set
1906
+
of characters without interior spaces, or as a string beginning with a "
1907
+
and ending with a ". Inside a " delimited string any character can
1908
+
occur, except for a " itself, which must be quoted using \ (back slash).
1909
+
1910
+
Because these files are text files several special encodings are
1911
+
necessary to allow arbitrary data to be loaded. In particular:
1912
+
1913
+
of the root.
1914
+
1915
+
@ A free standing @ is used to denote the current origin.
1916
+
1917
+
\X where X is any character other than a digit (0-9), is
1918
+
used to quote that character so that its special meaning
1919
+
does not apply. For example, "\." can be used to place
1920
+
a dot character in a label.
1921
+
1922
+
\DDD where each D is a digit is the octet corresponding to
1923
+
the decimal number described by DDD. The resulting
1924
+
octet is assumed to be text and is not checked for
1925
+
special meaning.
1926
+
1927
+
( ) Parentheses are used to group data that crosses a line
1928
+
boundary. In effect, line terminations are not
1929
+
recognized within parentheses.
1930
+
1931
+
; Semicolon is used to start a comment; the remainder of
1932
+
the line is ignored.
1933
+
1934
+
5.2. Use of master files to define zones
1935
+
1936
+
When a master file is used to load a zone, the operation should be
1937
+
suppressed if any errors are encountered in the master file. The
1938
+
rationale for this is that a single error can have widespread
1939
+
consequences. For example, suppose that the RRs defining a delegation
1940
+
have syntax errors; then the server will return authoritative name
1941
+
errors for all names in the subzone (except in the case where the
1942
+
subzone is also present on the server).
1943
+
1944
+
Several other validity checks that should be performed in addition to
1945
+
insuring that the file is syntactically correct:
1946
+
1947
+
1. All RRs in the file should have the same class.
1948
+
1949
+
2. Exactly one SOA RR should be present at the top of the zone.
1950
+
1951
+
3. If delegations are present and glue information is required,
1952
+
it should be present.
1953
+
1954
+
1955
+
1956
+
Mockapetris [Page 35]
1957
+
1958
+
RFC 1035 Domain Implementation and Specification November 1987
1959
+
1960
+
1961
+
4. Information present outside of the authoritative nodes in the
1962
+
zone should be glue information, rather than the result of an
1963
+
origin or similar error.
1964
+
1965
+
5.3. Master file example
1966
+
1967
+
The following is an example file which might be used to define the
1968
+
ISI.EDU zone.and is loaded with an origin of ISI.EDU:
1969
+
1970
+
@ IN SOA VENERA Action\.domains (
1971
+
20 ; SERIAL
1972
+
7200 ; REFRESH
1973
+
600 ; RETRY
1974
+
3600000; EXPIRE
1975
+
60) ; MINIMUM
1976
+
1977
+
NS A.ISI.EDU.
1978
+
NS VENERA
1979
+
NS VAXA
1980
+
MX 10 VENERA
1981
+
MX 20 VAXA
1982
+
1983
+
A A 26.3.0.103
1984
+
1985
+
VENERA A 10.1.0.52
1986
+
A 128.9.0.32
1987
+
1988
+
VAXA A 10.2.0.27
1989
+
A 128.9.0.33
1990
+
1991
+
1992
+
$INCLUDE <SUBSYS>ISI-MAILBOXES.TXT
1993
+
1994
+
Where the file <SUBSYS>ISI-MAILBOXES.TXT is:
1995
+
1996
+
MOE MB A.ISI.EDU.
1997
+
LARRY MB A.ISI.EDU.
1998
+
CURLEY MB A.ISI.EDU.
1999
+
STOOGES MG MOE
2000
+
MG LARRY
2001
+
MG CURLEY
2002
+
2003
+
Note the use of the \ character in the SOA RR to specify the responsible
2004
+
person mailbox "Action.domains@E.ISI.EDU".
2005
+
2006
+
2007
+
2008
+
2009
+
2010
+
2011
+
2012
+
Mockapetris [Page 36]
2013
+
2014
+
RFC 1035 Domain Implementation and Specification November 1987
2015
+
2016
+
2017
+
6. NAME SERVER IMPLEMENTATION
2018
+
2019
+
6.1. Architecture
2020
+
2021
+
The optimal structure for the name server will depend on the host
2022
+
operating system and whether the name server is integrated with resolver
2023
+
operations, either by supporting recursive service, or by sharing its
2024
+
database with a resolver. This section discusses implementation
2025
+
considerations for a name server which shares a database with a
2026
+
resolver, but most of these concerns are present in any name server.
2027
+
2028
+
6.1.1. Control
2029
+
2030
+
A name server must employ multiple concurrent activities, whether they
2031
+
are implemented as separate tasks in the host's OS or multiplexing
2032
+
inside a single name server program. It is simply not acceptable for a
2033
+
name server to block the service of UDP requests while it waits for TCP
2034
+
data for refreshing or query activities. Similarly, a name server
2035
+
should not attempt to provide recursive service without processing such
2036
+
requests in parallel, though it may choose to serialize requests from a
2037
+
single client, or to regard identical requests from the same client as
2038
+
duplicates. A name server should not substantially delay requests while
2039
+
it reloads a zone from master files or while it incorporates a newly
2040
+
refreshed zone into its database.
2041
+
2042
+
6.1.2. Database
2043
+
2044
+
While name server implementations are free to use any internal data
2045
+
structures they choose, the suggested structure consists of three major
2046
+
parts:
2047
+
2048
+
- A "catalog" data structure which lists the zones available to
2049
+
this server, and a "pointer" to the zone data structure. The
2050
+
main purpose of this structure is to find the nearest ancestor
2051
+
zone, if any, for arriving standard queries.
2052
+
2053
+
- Separate data structures for each of the zones held by the
2054
+
name server.
2055
+
2056
+
- A data structure for cached data. (or perhaps separate caches
2057
+
for different classes)
2058
+
2059
+
All of these data structures can be implemented an identical tree
2060
+
structure format, with different data chained off the nodes in different
2061
+
parts: in the catalog the data is pointers to zones, while in the zone
2062
+
and cache data structures, the data will be RRs. In designing the tree
2063
+
framework the designer should recognize that query processing will need
2064
+
to traverse the tree using case-insensitive label comparisons; and that
2065
+
2066
+
2067
+
2068
+
Mockapetris [Page 37]
2069
+
2070
+
RFC 1035 Domain Implementation and Specification November 1987
2071
+
2072
+
2073
+
in real data, a few nodes have a very high branching factor (100-1000 or
2074
+
more), but the vast majority have a very low branching factor (0-1).
2075
+
2076
+
One way to solve the case problem is to store the labels for each node
2077
+
in two pieces: a standardized-case representation of the label where all
2078
+
ASCII characters are in a single case, together with a bit mask that
2079
+
denotes which characters are actually of a different case. The
2080
+
branching factor diversity can be handled using a simple linked list for
2081
+
a node until the branching factor exceeds some threshold, and
2082
+
transitioning to a hash structure after the threshold is exceeded. In
2083
+
any case, hash structures used to store tree sections must insure that
2084
+
hash functions and procedures preserve the casing conventions of the
2085
+
DNS.
2086
+
2087
+
The use of separate structures for the different parts of the database
2088
+
is motivated by several factors:
2089
+
2090
+
- The catalog structure can be an almost static structure that
2091
+
need change only when the system administrator changes the
2092
+
zones supported by the server. This structure can also be
2093
+
used to store parameters used to control refreshing
2094
+
activities.
2095
+
2096
+
- The individual data structures for zones allow a zone to be
2097
+
replaced simply by changing a pointer in the catalog. Zone
2098
+
refresh operations can build a new structure and, when
2099
+
complete, splice it into the database via a simple pointer
2100
+
replacement. It is very important that when a zone is
2101
+
refreshed, queries should not use old and new data
2102
+
simultaneously.
2103
+
2104
+
- With the proper search procedures, authoritative data in zones
2105
+
will always "hide", and hence take precedence over, cached
2106
+
data.
2107
+
2108
+
- Errors in zone definitions that cause overlapping zones, etc.,
2109
+
may cause erroneous responses to queries, but problem
2110
+
determination is simplified, and the contents of one "bad"
2111
+
zone can't corrupt another.
2112
+
2113
+
- Since the cache is most frequently updated, it is most
2114
+
vulnerable to corruption during system restarts. It can also
2115
+
become full of expired RR data. In either case, it can easily
2116
+
be discarded without disturbing zone data.
2117
+
2118
+
A major aspect of database design is selecting a structure which allows
2119
+
the name server to deal with crashes of the name server's host. State
2120
+
information which a name server should save across system crashes
2121
+
2122
+
2123
+
2124
+
Mockapetris [Page 38]
2125
+
2126
+
RFC 1035 Domain Implementation and Specification November 1987
2127
+
2128
+
2129
+
includes the catalog structure (including the state of refreshing for
2130
+
each zone) and the zone data itself.
2131
+
2132
+
6.1.3. Time
2133
+
2134
+
Both the TTL data for RRs and the timing data for refreshing activities
2135
+
depends on 32 bit timers in units of seconds. Inside the database,
2136
+
refresh timers and TTLs for cached data conceptually "count down", while
2137
+
data in the zone stays with constant TTLs.
2138
+
2139
+
A recommended implementation strategy is to store time in two ways: as
2140
+
a relative increment and as an absolute time. One way to do this is to
2141
+
use positive 32 bit numbers for one type and negative numbers for the
2142
+
other. The RRs in zones use relative times; the refresh timers and
2143
+
cache data use absolute times. Absolute numbers are taken with respect
2144
+
to some known origin and converted to relative values when placed in the
2145
+
response to a query. When an absolute TTL is negative after conversion
2146
+
to relative, then the data is expired and should be ignored.
2147
+
2148
+
6.2. Standard query processing
2149
+
2150
+
The major algorithm for standard query processing is presented in
2151
+
[RFC-1034].
2152
+
2153
+
When processing queries with QCLASS=*, or some other QCLASS which
2154
+
matches multiple classes, the response should never be authoritative
2155
+
unless the server can guarantee that the response covers all classes.
2156
+
2157
+
When composing a response, RRs which are to be inserted in the
2158
+
additional section, but duplicate RRs in the answer or authority
2159
+
sections, may be omitted from the additional section.
2160
+
2161
+
When a response is so long that truncation is required, the truncation
2162
+
should start at the end of the response and work forward in the
2163
+
datagram. Thus if there is any data for the authority section, the
2164
+
answer section is guaranteed to be unique.
2165
+
2166
+
The MINIMUM value in the SOA should be used to set a floor on the TTL of
2167
+
data distributed from a zone. This floor function should be done when
2168
+
the data is copied into a response. This will allow future dynamic
2169
+
update protocols to change the SOA MINIMUM field without ambiguous
2170
+
semantics.
2171
+
2172
+
6.3. Zone refresh and reload processing
2173
+
2174
+
In spite of a server's best efforts, it may be unable to load zone data
2175
+
from a master file due to syntax errors, etc., or be unable to refresh a
2176
+
zone within the its expiration parameter. In this case, the name server
2177
+
2178
+
2179
+
2180
+
Mockapetris [Page 39]
2181
+
2182
+
RFC 1035 Domain Implementation and Specification November 1987
2183
+
2184
+
2185
+
should answer queries as if it were not supposed to possess the zone.
2186
+
2187
+
If a master is sending a zone out via AXFR, and a new version is created
2188
+
during the transfer, the master should continue to send the old version
2189
+
if possible. In any case, it should never send part of one version and
2190
+
part of another. If completion is not possible, the master should reset
2191
+
the connection on which the zone transfer is taking place.
2192
+
2193
+
6.4. Inverse queries (Optional)
2194
+
2195
+
Inverse queries are an optional part of the DNS. Name servers are not
2196
+
required to support any form of inverse queries. If a name server
2197
+
receives an inverse query that it does not support, it returns an error
2198
+
response with the "Not Implemented" error set in the header. While
2199
+
inverse query support is optional, all name servers must be at least
2200
+
able to return the error response.
2201
+
2202
+
6.4.1. The contents of inverse queries and responses Inverse
2203
+
queries reverse the mappings performed by standard query operations;
2204
+
while a standard query maps a domain name to a resource, an inverse
2205
+
query maps a resource to a domain name. For example, a standard query
2206
+
might bind a domain name to a host address; the corresponding inverse
2207
+
query binds the host address to a domain name.
2208
+
2209
+
Inverse queries take the form of a single RR in the answer section of
2210
+
the message, with an empty question section. The owner name of the
2211
+
query RR and its TTL are not significant. The response carries
2212
+
questions in the question section which identify all names possessing
2213
+
the query RR WHICH THE NAME SERVER KNOWS. Since no name server knows
2214
+
about all of the domain name space, the response can never be assumed to
2215
+
be complete. Thus inverse queries are primarily useful for database
2216
+
management and debugging activities. Inverse queries are NOT an
2217
+
acceptable method of mapping host addresses to host names; use the IN-
2218
+
ADDR.ARPA domain instead.
2219
+
2220
+
Where possible, name servers should provide case-insensitive comparisons
2221
+
for inverse queries. Thus an inverse query asking for an MX RR of
2222
+
"Venera.isi.edu" should get the same response as a query for
2223
+
"VENERA.ISI.EDU"; an inverse query for HINFO RR "IBM-PC UNIX" should
2224
+
produce the same result as an inverse query for "IBM-pc unix". However,
2225
+
this cannot be guaranteed because name servers may possess RRs that
2226
+
contain character strings but the name server does not know that the
2227
+
data is character.
2228
+
2229
+
When a name server processes an inverse query, it either returns:
2230
+
2231
+
1. zero, one, or multiple domain names for the specified
2232
+
resource as QNAMEs in the question section
2233
+
2234
+
2235
+
2236
+
Mockapetris [Page 40]
2237
+
2238
+
RFC 1035 Domain Implementation and Specification November 1987
2239
+
2240
+
2241
+
2. an error code indicating that the name server doesn't support
2242
+
inverse mapping of the specified resource type.
2243
+
2244
+
When the response to an inverse query contains one or more QNAMEs, the
2245
+
owner name and TTL of the RR in the answer section which defines the
2246
+
inverse query is modified to exactly match an RR found at the first
2247
+
QNAME.
2248
+
2249
+
RRs returned in the inverse queries cannot be cached using the same
2250
+
mechanism as is used for the replies to standard queries. One reason
2251
+
for this is that a name might have multiple RRs of the same type, and
2252
+
only one would appear. For example, an inverse query for a single
2253
+
address of a multiply homed host might create the impression that only
2254
+
one address existed.
2255
+
2256
+
6.4.2. Inverse query and response example The overall structure
2257
+
of an inverse query for retrieving the domain name that corresponds to
2258
+
Internet address 10.1.0.52 is shown below:
2259
+
2260
+
+-----------------------------------------+
2261
+
Header | OPCODE=IQUERY, ID=997 |
2262
+
+-----------------------------------------+
2263
+
Question | <empty> |
2264
+
+-----------------------------------------+
2265
+
Answer | <anyname> A IN 10.1.0.52 |
2266
+
+-----------------------------------------+
2267
+
Authority | <empty> |
2268
+
+-----------------------------------------+
2269
+
Additional | <empty> |
2270
+
+-----------------------------------------+
2271
+
2272
+
This query asks for a question whose answer is the Internet style
2273
+
address 10.1.0.52. Since the owner name is not known, any domain name
2274
+
can be used as a placeholder (and is ignored). A single octet of zero,
2275
+
signifying the root, is usually used because it minimizes the length of
2276
+
the message. The TTL of the RR is not significant. The response to
2277
+
this query might be:
2278
+
2279
+
2280
+
2281
+
2282
+
2283
+
2284
+
2285
+
2286
+
2287
+
2288
+
2289
+
2290
+
2291
+
2292
+
Mockapetris [Page 41]
2293
+
2294
+
RFC 1035 Domain Implementation and Specification November 1987
2295
+
2296
+
2297
+
+-----------------------------------------+
2298
+
Header | OPCODE=RESPONSE, ID=997 |
2299
+
+-----------------------------------------+
2300
+
Question |QTYPE=A, QCLASS=IN, QNAME=VENERA.ISI.EDU |
2301
+
+-----------------------------------------+
2302
+
Answer | VENERA.ISI.EDU A IN 10.1.0.52 |
2303
+
+-----------------------------------------+
2304
+
Authority | <empty> |
2305
+
+-----------------------------------------+
2306
+
Additional | <empty> |
2307
+
+-----------------------------------------+
2308
+
2309
+
Note that the QTYPE in a response to an inverse query is the same as the
2310
+
TYPE field in the answer section of the inverse query. Responses to
2311
+
inverse queries may contain multiple questions when the inverse is not
2312
+
unique. If the question section in the response is not empty, then the
2313
+
RR in the answer section is modified to correspond to be an exact copy
2314
+
of an RR at the first QNAME.
2315
+
2316
+
6.4.3. Inverse query processing
2317
+
2318
+
Name servers that support inverse queries can support these operations
2319
+
through exhaustive searches of their databases, but this becomes
2320
+
impractical as the size of the database increases. An alternative
2321
+
approach is to invert the database according to the search key.
2322
+
2323
+
For name servers that support multiple zones and a large amount of data,
2324
+
the recommended approach is separate inversions for each zone. When a
2325
+
particular zone is changed during a refresh, only its inversions need to
2326
+
be redone.
2327
+
2328
+
Support for transfer of this type of inversion may be included in future
2329
+
versions of the domain system, but is not supported in this version.
2330
+
2331
+
6.5. Completion queries and responses
2332
+
2333
+
The optional completion services described in RFC-882 and RFC-883 have
2334
+
been deleted. Redesigned services may become available in the future.
2335
+
2336
+
2337
+
2338
+
2339
+
2340
+
2341
+
2342
+
2343
+
2344
+
2345
+
2346
+
2347
+
2348
+
Mockapetris [Page 42]
2349
+
2350
+
RFC 1035 Domain Implementation and Specification November 1987
2351
+
2352
+
2353
+
7. RESOLVER IMPLEMENTATION
2354
+
2355
+
The top levels of the recommended resolver algorithm are discussed in
2356
+
[RFC-1034]. This section discusses implementation details assuming the
2357
+
database structure suggested in the name server implementation section
2358
+
of this memo.
2359
+
2360
+
7.1. Transforming a user request into a query
2361
+
2362
+
The first step a resolver takes is to transform the client's request,
2363
+
stated in a format suitable to the local OS, into a search specification
2364
+
for RRs at a specific name which match a specific QTYPE and QCLASS.
2365
+
Where possible, the QTYPE and QCLASS should correspond to a single type
2366
+
and a single class, because this makes the use of cached data much
2367
+
simpler. The reason for this is that the presence of data of one type
2368
+
in a cache doesn't confirm the existence or non-existence of data of
2369
+
other types, hence the only way to be sure is to consult an
2370
+
authoritative source. If QCLASS=* is used, then authoritative answers
2371
+
won't be available.
2372
+
2373
+
Since a resolver must be able to multiplex multiple requests if it is to
2374
+
perform its function efficiently, each pending request is usually
2375
+
represented in some block of state information. This state block will
2376
+
typically contain:
2377
+
2378
+
- A timestamp indicating the time the request began.
2379
+
The timestamp is used to decide whether RRs in the database
2380
+
can be used or are out of date. This timestamp uses the
2381
+
absolute time format previously discussed for RR storage in
2382
+
zones and caches. Note that when an RRs TTL indicates a
2383
+
relative time, the RR must be timely, since it is part of a
2384
+
zone. When the RR has an absolute time, it is part of a
2385
+
cache, and the TTL of the RR is compared against the timestamp
2386
+
for the start of the request.
2387
+
2388
+
Note that using the timestamp is superior to using a current
2389
+
time, since it allows RRs with TTLs of zero to be entered in
2390
+
the cache in the usual manner, but still used by the current
2391
+
request, even after intervals of many seconds due to system
2392
+
load, query retransmission timeouts, etc.
2393
+
2394
+
- Some sort of parameters to limit the amount of work which will
2395
+
be performed for this request.
2396
+
2397
+
The amount of work which a resolver will do in response to a
2398
+
client request must be limited to guard against errors in the
2399
+
database, such as circular CNAME references, and operational
2400
+
problems, such as network partition which prevents the
2401
+
2402
+
2403
+
2404
+
Mockapetris [Page 43]
2405
+
2406
+
RFC 1035 Domain Implementation and Specification November 1987
2407
+
2408
+
2409
+
resolver from accessing the name servers it needs. While
2410
+
local limits on the number of times a resolver will retransmit
2411
+
a particular query to a particular name server address are
2412
+
essential, the resolver should have a global per-request
2413
+
counter to limit work on a single request. The counter should
2414
+
be set to some initial value and decremented whenever the
2415
+
resolver performs any action (retransmission timeout,
2416
+
retransmission, etc.) If the counter passes zero, the request
2417
+
is terminated with a temporary error.
2418
+
2419
+
Note that if the resolver structure allows one request to
2420
+
start others in parallel, such as when the need to access a
2421
+
name server for one request causes a parallel resolve for the
2422
+
name server's addresses, the spawned request should be started
2423
+
with a lower counter. This prevents circular references in
2424
+
the database from starting a chain reaction of resolver
2425
+
activity.
2426
+
2427
+
- The SLIST data structure discussed in [RFC-1034].
2428
+
2429
+
This structure keeps track of the state of a request if it
2430
+
must wait for answers from foreign name servers.
2431
+
2432
+
7.2. Sending the queries
2433
+
2434
+
As described in [RFC-1034], the basic task of the resolver is to
2435
+
formulate a query which will answer the client's request and direct that
2436
+
query to name servers which can provide the information. The resolver
2437
+
will usually only have very strong hints about which servers to ask, in
2438
+
the form of NS RRs, and may have to revise the query, in response to
2439
+
CNAMEs, or revise the set of name servers the resolver is asking, in
2440
+
response to delegation responses which point the resolver to name
2441
+
servers closer to the desired information. In addition to the
2442
+
information requested by the client, the resolver may have to call upon
2443
+
its own services to determine the address of name servers it wishes to
2444
+
contact.
2445
+
2446
+
In any case, the model used in this memo assumes that the resolver is
2447
+
multiplexing attention between multiple requests, some from the client,
2448
+
and some internally generated. Each request is represented by some
2449
+
state information, and the desired behavior is that the resolver
2450
+
transmit queries to name servers in a way that maximizes the probability
2451
+
that the request is answered, minimizes the time that the request takes,
2452
+
and avoids excessive transmissions. The key algorithm uses the state
2453
+
information of the request to select the next name server address to
2454
+
query, and also computes a timeout which will cause the next action
2455
+
should a response not arrive. The next action will usually be a
2456
+
transmission to some other server, but may be a temporary error to the
2457
+
2458
+
2459
+
2460
+
Mockapetris [Page 44]
2461
+
2462
+
RFC 1035 Domain Implementation and Specification November 1987
2463
+
2464
+
2465
+
client.
2466
+
2467
+
The resolver always starts with a list of server names to query (SLIST).
2468
+
This list will be all NS RRs which correspond to the nearest ancestor
2469
+
zone that the resolver knows about. To avoid startup problems, the
2470
+
resolver should have a set of default servers which it will ask should
2471
+
it have no current NS RRs which are appropriate. The resolver then adds
2472
+
to SLIST all of the known addresses for the name servers, and may start
2473
+
parallel requests to acquire the addresses of the servers when the
2474
+
resolver has the name, but no addresses, for the name servers.
2475
+
2476
+
To complete initialization of SLIST, the resolver attaches whatever
2477
+
history information it has to the each address in SLIST. This will
2478
+
usually consist of some sort of weighted averages for the response time
2479
+
of the address, and the batting average of the address (i.e., how often
2480
+
the address responded at all to the request). Note that this
2481
+
information should be kept on a per address basis, rather than on a per
2482
+
name server basis, because the response time and batting average of a
2483
+
particular server may vary considerably from address to address. Note
2484
+
also that this information is actually specific to a resolver address /
2485
+
server address pair, so a resolver with multiple addresses may wish to
2486
+
keep separate histories for each of its addresses. Part of this step
2487
+
must deal with addresses which have no such history; in this case an
2488
+
expected round trip time of 5-10 seconds should be the worst case, with
2489
+
lower estimates for the same local network, etc.
2490
+
2491
+
Note that whenever a delegation is followed, the resolver algorithm
2492
+
reinitializes SLIST.
2493
+
2494
+
The information establishes a partial ranking of the available name
2495
+
server addresses. Each time an address is chosen and the state should
2496
+
be altered to prevent its selection again until all other addresses have
2497
+
been tried. The timeout for each transmission should be 50-100% greater
2498
+
than the average predicted value to allow for variance in response.
2499
+
2500
+
Some fine points:
2501
+
2502
+
- The resolver may encounter a situation where no addresses are
2503
+
available for any of the name servers named in SLIST, and
2504
+
where the servers in the list are precisely those which would
2505
+
normally be used to look up their own addresses. This
2506
+
situation typically occurs when the glue address RRs have a
2507
+
smaller TTL than the NS RRs marking delegation, or when the
2508
+
resolver caches the result of a NS search. The resolver
2509
+
should detect this condition and restart the search at the
2510
+
next ancestor zone, or alternatively at the root.
2511
+
2512
+
2513
+
2514
+
2515
+
2516
+
Mockapetris [Page 45]
2517
+
2518
+
RFC 1035 Domain Implementation and Specification November 1987
2519
+
2520
+
2521
+
- If a resolver gets a server error or other bizarre response
2522
+
from a name server, it should remove it from SLIST, and may
2523
+
wish to schedule an immediate transmission to the next
2524
+
candidate server address.
2525
+
2526
+
7.3. Processing responses
2527
+
2528
+
The first step in processing arriving response datagrams is to parse the
2529
+
response. This procedure should include:
2530
+
2531
+
- Check the header for reasonableness. Discard datagrams which
2532
+
are queries when responses are expected.
2533
+
2534
+
- Parse the sections of the message, and insure that all RRs are
2535
+
correctly formatted.
2536
+
2537
+
- As an optional step, check the TTLs of arriving data looking
2538
+
for RRs with excessively long TTLs. If a RR has an
2539
+
excessively long TTL, say greater than 1 week, either discard
2540
+
the whole response, or limit all TTLs in the response to 1
2541
+
week.
2542
+
2543
+
The next step is to match the response to a current resolver request.
2544
+
The recommended strategy is to do a preliminary matching using the ID
2545
+
field in the domain header, and then to verify that the question section
2546
+
corresponds to the information currently desired. This requires that
2547
+
the transmission algorithm devote several bits of the domain ID field to
2548
+
a request identifier of some sort. This step has several fine points:
2549
+
2550
+
- Some name servers send their responses from different
2551
+
addresses than the one used to receive the query. That is, a
2552
+
resolver cannot rely that a response will come from the same
2553
+
address which it sent the corresponding query to. This name
2554
+
server bug is typically encountered in UNIX systems.
2555
+
2556
+
- If the resolver retransmits a particular request to a name
2557
+
server it should be able to use a response from any of the
2558
+
transmissions. However, if it is using the response to sample
2559
+
the round trip time to access the name server, it must be able
2560
+
to determine which transmission matches the response (and keep
2561
+
transmission times for each outgoing message), or only
2562
+
calculate round trip times based on initial transmissions.
2563
+
2564
+
- A name server will occasionally not have a current copy of a
2565
+
zone which it should have according to some NS RRs. The
2566
+
resolver should simply remove the name server from the current
2567
+
SLIST, and continue.
2568
+
2569
+
2570
+
2571
+
2572
+
Mockapetris [Page 46]
2573
+
2574
+
RFC 1035 Domain Implementation and Specification November 1987
2575
+
2576
+
2577
+
7.4. Using the cache
2578
+
2579
+
In general, we expect a resolver to cache all data which it receives in
2580
+
responses since it may be useful in answering future client requests.
2581
+
However, there are several types of data which should not be cached:
2582
+
2583
+
- When several RRs of the same type are available for a
2584
+
particular owner name, the resolver should either cache them
2585
+
all or none at all. When a response is truncated, and a
2586
+
resolver doesn't know whether it has a complete set, it should
2587
+
not cache a possibly partial set of RRs.
2588
+
2589
+
- Cached data should never be used in preference to
2590
+
authoritative data, so if caching would cause this to happen
2591
+
the data should not be cached.
2592
+
2593
+
- The results of an inverse query should not be cached.
2594
+
2595
+
- The results of standard queries where the QNAME contains "*"
2596
+
labels if the data might be used to construct wildcards. The
2597
+
reason is that the cache does not necessarily contain existing
2598
+
RRs or zone boundary information which is necessary to
2599
+
restrict the application of the wildcard RRs.
2600
+
2601
+
- RR data in responses of dubious reliability. When a resolver
2602
+
receives unsolicited responses or RR data other than that
2603
+
requested, it should discard it without caching it. The basic
2604
+
implication is that all sanity checks on a packet should be
2605
+
performed before any of it is cached.
2606
+
2607
+
In a similar vein, when a resolver has a set of RRs for some name in a
2608
+
response, and wants to cache the RRs, it should check its cache for
2609
+
already existing RRs. Depending on the circumstances, either the data
2610
+
in the response or the cache is preferred, but the two should never be
2611
+
combined. If the data in the response is from authoritative data in the
2612
+
answer section, it is always preferred.
2613
+
2614
+
8. MAIL SUPPORT
2615
+
2616
+
The domain system defines a standard for mapping mailboxes into domain
2617
+
names, and two methods for using the mailbox information to derive mail
2618
+
routing information. The first method is called mail exchange binding
2619
+
and the other method is mailbox binding. The mailbox encoding standard
2620
+
and mail exchange binding are part of the DNS official protocol, and are
2621
+
the recommended method for mail routing in the Internet. Mailbox
2622
+
binding is an experimental feature which is still under development and
2623
+
subject to change.
2624
+
2625
+
2626
+
2627
+
2628
+
Mockapetris [Page 47]
2629
+
2630
+
RFC 1035 Domain Implementation and Specification November 1987
2631
+
2632
+
2633
+
The mailbox encoding standard assumes a mailbox name of the form
2634
+
"<local-part>@<mail-domain>". While the syntax allowed in each of these
2635
+
sections varies substantially between the various mail internets, the
2636
+
preferred syntax for the ARPA Internet is given in [RFC-822].
2637
+
2638
+
The DNS encodes the <local-part> as a single label, and encodes the
2639
+
<mail-domain> as a domain name. The single label from the <local-part>
2640
+
is prefaced to the domain name from <mail-domain> to form the domain
2641
+
name corresponding to the mailbox. Thus the mailbox HOSTMASTER@SRI-
2642
+
NIC.ARPA is mapped into the domain name HOSTMASTER.SRI-NIC.ARPA. If the
2643
+
<local-part> contains dots or other special characters, its
2644
+
representation in a master file will require the use of backslash
2645
+
quoting to ensure that the domain name is properly encoded. For
2646
+
example, the mailbox Action.domains@ISI.EDU would be represented as
2647
+
Action\.domains.ISI.EDU.
2648
+
2649
+
8.1. Mail exchange binding
2650
+
2651
+
Mail exchange binding uses the <mail-domain> part of a mailbox
2652
+
specification to determine where mail should be sent. The <local-part>
2653
+
is not even consulted. [RFC-974] specifies this method in detail, and
2654
+
should be consulted before attempting to use mail exchange support.
2655
+
2656
+
One of the advantages of this method is that it decouples mail
2657
+
destination naming from the hosts used to support mail service, at the
2658
+
cost of another layer of indirection in the lookup function. However,
2659
+
the addition layer should eliminate the need for complicated "%", "!",
2660
+
etc encodings in <local-part>.
2661
+
2662
+
The essence of the method is that the <mail-domain> is used as a domain
2663
+
name to locate type MX RRs which list hosts willing to accept mail for
2664
+
<mail-domain>, together with preference values which rank the hosts
2665
+
according to an order specified by the administrators for <mail-domain>.
2666
+
2667
+
In this memo, the <mail-domain> ISI.EDU is used in examples, together
2668
+
with the hosts VENERA.ISI.EDU and VAXA.ISI.EDU as mail exchanges for
2669
+
ISI.EDU. If a mailer had a message for Mockapetris@ISI.EDU, it would
2670
+
route it by looking up MX RRs for ISI.EDU. The MX RRs at ISI.EDU name
2671
+
VENERA.ISI.EDU and VAXA.ISI.EDU, and type A queries can find the host
2672
+
addresses.
2673
+
2674
+
8.2. Mailbox binding (Experimental)
2675
+
2676
+
In mailbox binding, the mailer uses the entire mail destination
2677
+
specification to construct a domain name. The encoded domain name for
2678
+
the mailbox is used as the QNAME field in a QTYPE=MAILB query.
2679
+
2680
+
Several outcomes are possible for this query:
2681
+
2682
+
2683
+
2684
+
Mockapetris [Page 48]
2685
+
2686
+
RFC 1035 Domain Implementation and Specification November 1987
2687
+
2688
+
2689
+
1. The query can return a name error indicating that the mailbox
2690
+
does not exist as a domain name.
2691
+
2692
+
In the long term, this would indicate that the specified
2693
+
mailbox doesn't exist. However, until the use of mailbox
2694
+
binding is universal, this error condition should be
2695
+
interpreted to mean that the organization identified by the
2696
+
global part does not support mailbox binding. The
2697
+
appropriate procedure is to revert to exchange binding at
2698
+
this point.
2699
+
2700
+
2. The query can return a Mail Rename (MR) RR.
2701
+
2702
+
The MR RR carries new mailbox specification in its RDATA
2703
+
field. The mailer should replace the old mailbox with the
2704
+
new one and retry the operation.
2705
+
2706
+
3. The query can return a MB RR.
2707
+
2708
+
The MB RR carries a domain name for a host in its RDATA
2709
+
field. The mailer should deliver the message to that host
2710
+
via whatever protocol is applicable, e.g., b,SMTP.
2711
+
2712
+
4. The query can return one or more Mail Group (MG) RRs.
2713
+
2714
+
This condition means that the mailbox was actually a mailing
2715
+
list or mail group, rather than a single mailbox. Each MG RR
2716
+
has a RDATA field that identifies a mailbox that is a member
2717
+
of the group. The mailer should deliver a copy of the
2718
+
message to each member.
2719
+
2720
+
5. The query can return a MB RR as well as one or more MG RRs.
2721
+
2722
+
This condition means the the mailbox was actually a mailing
2723
+
list. The mailer can either deliver the message to the host
2724
+
specified by the MB RR, which will in turn do the delivery to
2725
+
all members, or the mailer can use the MG RRs to do the
2726
+
expansion itself.
2727
+
2728
+
In any of these cases, the response may include a Mail Information
2729
+
(MINFO) RR. This RR is usually associated with a mail group, but is
2730
+
legal with a MB. The MINFO RR identifies two mailboxes. One of these
2731
+
identifies a responsible person for the original mailbox name. This
2732
+
mailbox should be used for requests to be added to a mail group, etc.
2733
+
The second mailbox name in the MINFO RR identifies a mailbox that should
2734
+
receive error messages for mail failures. This is particularly
2735
+
appropriate for mailing lists when errors in member names should be
2736
+
reported to a person other than the one who sends a message to the list.
2737
+
2738
+
2739
+
2740
+
Mockapetris [Page 49]
2741
+
2742
+
RFC 1035 Domain Implementation and Specification November 1987
2743
+
2744
+
2745
+
New fields may be added to this RR in the future.
2746
+
2747
+
2748
+
9. REFERENCES and BIBLIOGRAPHY
2749
+
2750
+
[Dyer 87] S. Dyer, F. Hsu, "Hesiod", Project Athena
2751
+
Technical Plan - Name Service, April 1987, version 1.9.
2752
+
2753
+
Describes the fundamentals of the Hesiod name service.
2754
+
2755
+
[IEN-116] J. Postel, "Internet Name Server", IEN-116,
2756
+
USC/Information Sciences Institute, August 1979.
2757
+
2758
+
A name service obsoleted by the Domain Name System, but
2759
+
still in use.
2760
+
2761
+
[Quarterman 86] J. Quarterman, and J. Hoskins, "Notable Computer Networks",
2762
+
Communications of the ACM, October 1986, volume 29, number
2763
+
10.
2764
+
2765
+
[RFC-742] K. Harrenstien, "NAME/FINGER", RFC-742, Network
2766
+
Information Center, SRI International, December 1977.
2767
+
2768
+
[RFC-768] J. Postel, "User Datagram Protocol", RFC-768,
2769
+
USC/Information Sciences Institute, August 1980.
2770
+
2771
+
[RFC-793] J. Postel, "Transmission Control Protocol", RFC-793,
2772
+
USC/Information Sciences Institute, September 1981.
2773
+
2774
+
[RFC-799] D. Mills, "Internet Name Domains", RFC-799, COMSAT,
2775
+
September 1981.
2776
+
2777
+
Suggests introduction of a hierarchy in place of a flat
2778
+
name space for the Internet.
2779
+
2780
+
[RFC-805] J. Postel, "Computer Mail Meeting Notes", RFC-805,
2781
+
USC/Information Sciences Institute, February 1982.
2782
+
2783
+
[RFC-810] E. Feinler, K. Harrenstien, Z. Su, and V. White, "DOD
2784
+
Internet Host Table Specification", RFC-810, Network
2785
+
Information Center, SRI International, March 1982.
2786
+
2787
+
Obsolete. See RFC-952.
2788
+
2789
+
[RFC-811] K. Harrenstien, V. White, and E. Feinler, "Hostnames
2790
+
Server", RFC-811, Network Information Center, SRI
2791
+
International, March 1982.
2792
+
2793
+
2794
+
2795
+
2796
+
Mockapetris [Page 50]
2797
+
2798
+
RFC 1035 Domain Implementation and Specification November 1987
2799
+
2800
+
2801
+
Obsolete. See RFC-953.
2802
+
2803
+
[RFC-812] K. Harrenstien, and V. White, "NICNAME/WHOIS", RFC-812,
2804
+
Network Information Center, SRI International, March
2805
+
1982.
2806
+
2807
+
[RFC-819] Z. Su, and J. Postel, "The Domain Naming Convention for
2808
+
Internet User Applications", RFC-819, Network
2809
+
Information Center, SRI International, August 1982.
2810
+
2811
+
Early thoughts on the design of the domain system.
2812
+
Current implementation is completely different.
2813
+
2814
+
[RFC-821] J. Postel, "Simple Mail Transfer Protocol", RFC-821,
2815
+
USC/Information Sciences Institute, August 1980.
2816
+
2817
+
[RFC-830] Z. Su, "A Distributed System for Internet Name Service",
2818
+
RFC-830, Network Information Center, SRI International,
2819
+
October 1982.
2820
+
2821
+
Early thoughts on the design of the domain system.
2822
+
Current implementation is completely different.
2823
+
2824
+
[RFC-882] P. Mockapetris, "Domain names - Concepts and
2825
+
Facilities," RFC-882, USC/Information Sciences
2826
+
Institute, November 1983.
2827
+
2828
+
Superceeded by this memo.
2829
+
2830
+
[RFC-883] P. Mockapetris, "Domain names - Implementation and
2831
+
Specification," RFC-883, USC/Information Sciences
2832
+
Institute, November 1983.
2833
+
2834
+
Superceeded by this memo.
2835
+
2836
+
[RFC-920] J. Postel and J. Reynolds, "Domain Requirements",
2837
+
RFC-920, USC/Information Sciences Institute,
2838
+
October 1984.
2839
+
2840
+
Explains the naming scheme for top level domains.
2841
+
2842
+
[RFC-952] K. Harrenstien, M. Stahl, E. Feinler, "DoD Internet Host
2843
+
Table Specification", RFC-952, SRI, October 1985.
2844
+
2845
+
Specifies the format of HOSTS.TXT, the host/address
2846
+
table replaced by the DNS.
2847
+
2848
+
2849
+
2850
+
2851
+
2852
+
Mockapetris [Page 51]
2853
+
2854
+
RFC 1035 Domain Implementation and Specification November 1987
2855
+
2856
+
2857
+
[RFC-953] K. Harrenstien, M. Stahl, E. Feinler, "HOSTNAME Server",
2858
+
RFC-953, SRI, October 1985.
2859
+
2860
+
This RFC contains the official specification of the
2861
+
hostname server protocol, which is obsoleted by the DNS.
2862
+
This TCP based protocol accesses information stored in
2863
+
the RFC-952 format, and is used to obtain copies of the
2864
+
host table.
2865
+
2866
+
[RFC-973] P. Mockapetris, "Domain System Changes and
2867
+
Observations", RFC-973, USC/Information Sciences
2868
+
Institute, January 1986.
2869
+
2870
+
Describes changes to RFC-882 and RFC-883 and reasons for
2871
+
them.
2872
+
2873
+
[RFC-974] C. Partridge, "Mail routing and the domain system",
2874
+
RFC-974, CSNET CIC BBN Labs, January 1986.
2875
+
2876
+
Describes the transition from HOSTS.TXT based mail
2877
+
addressing to the more powerful MX system used with the
2878
+
domain system.
2879
+
2880
+
[RFC-1001] NetBIOS Working Group, "Protocol standard for a NetBIOS
2881
+
service on a TCP/UDP transport: Concepts and Methods",
2882
+
RFC-1001, March 1987.
2883
+
2884
+
This RFC and RFC-1002 are a preliminary design for
2885
+
NETBIOS on top of TCP/IP which proposes to base NetBIOS
2886
+
name service on top of the DNS.
2887
+
2888
+
[RFC-1002] NetBIOS Working Group, "Protocol standard for a NetBIOS
2889
+
service on a TCP/UDP transport: Detailed
2890
+
Specifications", RFC-1002, March 1987.
2891
+
2892
+
[RFC-1010] J. Reynolds, and J. Postel, "Assigned Numbers", RFC-1010,
2893
+
USC/Information Sciences Institute, May 1987.
2894
+
2895
+
Contains socket numbers and mnemonics for host names,
2896
+
operating systems, etc.
2897
+
2898
+
[RFC-1031] W. Lazear, "MILNET Name Domain Transition", RFC-1031,
2899
+
November 1987.
2900
+
2901
+
Describes a plan for converting the MILNET to the DNS.
2902
+
2903
+
[RFC-1032] M. Stahl, "Establishing a Domain - Guidelines for
2904
+
Administrators", RFC-1032, November 1987.
2905
+
2906
+
2907
+
2908
+
Mockapetris [Page 52]
2909
+
2910
+
RFC 1035 Domain Implementation and Specification November 1987
2911
+
2912
+
2913
+
Describes the registration policies used by the NIC to
2914
+
administer the top level domains and delegate subzones.
2915
+
2916
+
[RFC-1033] M. Lottor, "Domain Administrators Operations Guide",
2917
+
RFC-1033, November 1987.
2918
+
2919
+
A cookbook for domain administrators.
2920
+
2921
+
[Solomon 82] M. Solomon, L. Landweber, and D. Neuhengen, "The CSNET
2922
+
Name Server", Computer Networks, vol 6, nr 3, July 1982.
2923
+
2924
+
Describes a name service for CSNET which is independent
2925
+
from the DNS and DNS use in the CSNET.
2926
+
2927
+
2928
+
2929
+
2930
+
2931
+
2932
+
2933
+
2934
+
2935
+
2936
+
2937
+
2938
+
2939
+
2940
+
2941
+
2942
+
2943
+
2944
+
2945
+
2946
+
2947
+
2948
+
2949
+
2950
+
2951
+
2952
+
2953
+
2954
+
2955
+
2956
+
2957
+
2958
+
2959
+
2960
+
2961
+
2962
+
2963
+
2964
+
Mockapetris [Page 53]
2965
+
2966
+
RFC 1035 Domain Implementation and Specification November 1987
2967
+
2968
+
2969
+
Index
2970
+
2971
+
* 13
2972
+
2973
+
; 33, 35
2974
+
2975
+
<character-string> 35
2976
+
<domain-name> 34
2977
+
2978
+
@ 35
2979
+
2980
+
\ 35
2981
+
2982
+
A 12
2983
+
2984
+
Byte order 8
2985
+
2986
+
CH 13
2987
+
Character case 9
2988
+
CLASS 11
2989
+
CNAME 12
2990
+
Completion 42
2991
+
CS 13
2992
+
2993
+
Hesiod 13
2994
+
HINFO 12
2995
+
HS 13
2996
+
2997
+
IN 13
2998
+
IN-ADDR.ARPA domain 22
2999
+
Inverse queries 40
3000
+
3001
+
Mailbox names 47
3002
+
MB 12
3003
+
MD 12
3004
+
MF 12
3005
+
MG 12
3006
+
MINFO 12
3007
+
MINIMUM 20
3008
+
MR 12
3009
+
MX 12
3010
+
3011
+
NS 12
3012
+
NULL 12
3013
+
3014
+
Port numbers 32
3015
+
Primary server 5
3016
+
PTR 12, 18
3017
+
3018
+
3019
+
3020
+
Mockapetris [Page 54]
3021
+
3022
+
RFC 1035 Domain Implementation and Specification November 1987
3023
+
3024
+
3025
+
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spec/rfc5891.txt
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Internet Engineering Task Force (IETF) J. Klensin
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Request for Comments: 5891 August 2010
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Obsoletes: 3490, 3491
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Updates: 3492
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Category: Standards Track
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ISSN: 2070-1721
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Internationalized Domain Names in Applications (IDNA): Protocol
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Abstract
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This document is the revised protocol definition for
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Internationalized Domain Names (IDNs). The rationale for changes,
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the relationship to the older specification, and important
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terminology are provided in other documents. This document specifies
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the protocol mechanism, called Internationalized Domain Names in
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Applications (IDNA), for registering and looking up IDNs in a way
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that does not require changes to the DNS itself. IDNA is only meant
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for processing domain names, not free text.
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Status of This Memo
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This is an Internet Standards Track document.
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This document is a product of the Internet Engineering Task Force
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(IETF). It represents the consensus of the IETF community. It has
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received public review and has been approved for publication by the
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Internet Engineering Steering Group (IESG). Further information on
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Internet Standards is available in Section 2 of RFC 5741.
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Information about the current status of this document, any errata,
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and how to provide feedback on it may be obtained at
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http://www.rfc-editor.org/info/rfc5891.
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Klensin Standards Track [Page 1]
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RFC 5891 IDNA2008 Protocol August 2010
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Copyright Notice
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Copyright (c) 2010 IETF Trust and the persons identified as the
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document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
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Provisions Relating to IETF Documents
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(http://trustee.ietf.org/license-info) in effect on the date of
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publication of this document. Please review these documents
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carefully, as they describe your rights and restrictions with respect
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to this document. Code Components extracted from this document must
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include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
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described in the Simplified BSD License.
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This document may contain material from IETF Documents or IETF
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Contributions published or made publicly available before November
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10, 2008. The person(s) controlling the copyright in some of this
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material may not have granted the IETF Trust the right to allow
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modifications of such material outside the IETF Standards Process.
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Without obtaining an adequate license from the person(s) controlling
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the copyright in such materials, this document may not be modified
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outside the IETF Standards Process, and derivative works of it may
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not be created outside the IETF Standards Process, except to format
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it for publication as an RFC or to translate it into languages other
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than English.
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Klensin Standards Track [Page 2]
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RFC 5891 IDNA2008 Protocol August 2010
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Table of Contents
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
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2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
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3. Requirements and Applicability . . . . . . . . . . . . . . . . 5
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3.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 5
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3.2. Applicability . . . . . . . . . . . . . . . . . . . . . . 5
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3.2.1. DNS Resource Records . . . . . . . . . . . . . . . . . 6
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3.2.2. Non-Domain-Name Data Types Stored in the DNS . . . . . 6
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4. Registration Protocol . . . . . . . . . . . . . . . . . . . . 6
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4.1. Input to IDNA Registration . . . . . . . . . . . . . . . . 7
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4.2. Permitted Character and Label Validation . . . . . . . . . 7
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4.2.1. Input Format . . . . . . . . . . . . . . . . . . . . . 7
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4.2.2. Rejection of Characters That Are Not Permitted . . . . 8
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4.2.3. Label Validation . . . . . . . . . . . . . . . . . . . 8
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4.2.4. Registration Validation Requirements . . . . . . . . . 9
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4.3. Registry Restrictions . . . . . . . . . . . . . . . . . . 9
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4.4. Punycode Conversion . . . . . . . . . . . . . . . . . . . 9
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4.5. Insertion in the Zone . . . . . . . . . . . . . . . . . . 10
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5. Domain Name Lookup Protocol . . . . . . . . . . . . . . . . . 10
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5.1. Label String Input . . . . . . . . . . . . . . . . . . . . 10
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5.2. Conversion to Unicode . . . . . . . . . . . . . . . . . . 10
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5.3. A-label Input . . . . . . . . . . . . . . . . . . . . . . 10
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5.4. Validation and Character List Testing . . . . . . . . . . 11
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5.5. Punycode Conversion . . . . . . . . . . . . . . . . . . . 13
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5.6. DNS Name Resolution . . . . . . . . . . . . . . . . . . . 13
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6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
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7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
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8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 13
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9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14
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10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
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10.1. Normative References . . . . . . . . . . . . . . . . . . . 14
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10.2. Informative References . . . . . . . . . . . . . . . . . . 15
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Appendix A. Summary of Major Changes from IDNA2003 . . . . . . . 17
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1. Introduction
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This document supplies the protocol definition for Internationalized
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Domain Names in Applications (IDNA), with the version specified here
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known as IDNA2008. Essential definitions and terminology for
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understanding this document and a road map of the collection of
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documents that make up IDNA2008 appear in a separate Definitions
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document [RFC5890]. Appendix A discusses the relationship between
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this specification and the earlier version of IDNA (referred to here
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as "IDNA2003"). The rationale for these changes, along with
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considerable explanatory material and advice to zone administrators
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who support IDNs, is provided in another document, known informally
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in this series as the "Rationale document" [RFC5894].
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IDNA works by allowing applications to use certain ASCII [ASCII]
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string labels (beginning with a special prefix) to represent
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non-ASCII name labels. Lower-layer protocols need not be aware of
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this; therefore, IDNA does not change any infrastructure. In
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particular, IDNA does not depend on any changes to DNS servers,
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resolvers, or DNS protocol elements, because the ASCII name service
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provided by the existing DNS can be used for IDNA.
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IDNA applies only to a specific subset of DNS labels. The base DNS
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standards [RFC1034] [RFC1035] and their various updates specify how
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to combine labels into fully-qualified domain names and parse labels
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out of those names.
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This document describes two separate protocols, one for IDN
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registration (Section 4) and one for IDN lookup (Section 5). These
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two protocols share some terminology, reference data, and operations.
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2. Terminology
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As mentioned above, terminology used as part of the definition of
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IDNA appears in the Definitions document [RFC5890]. It is worth
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noting that some of this terminology overlaps with, and is consistent
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with, that used in Unicode or other character set standards and the
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DNS. Readers of this document are assumed to be familiar with the
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associated Definitions document and with the DNS-specific terminology
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in RFC 1034 [RFC1034].
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The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
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"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
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document are to be interpreted as described in BCP 14, RFC 2119
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[RFC2119].
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3. Requirements and Applicability
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3.1. Requirements
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IDNA makes the following requirements:
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1. Whenever a domain name is put into a domain name slot that is not
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IDNA-aware (see Section 2.3.2.6 of the Definitions document
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[RFC5890]), it MUST contain only ASCII characters (i.e., its
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labels must be either A-labels or NR-LDH labels), unless the DNS
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application is not subject to historical recommendations for
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"hostname"-style names (see RFC 1034 [RFC1034] and
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Section 3.2.1).
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2. Labels MUST be compared using equivalent forms: either both
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A-label forms or both U-label forms. Because A-labels and
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U-labels can be transformed into each other without loss of
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information, these comparisons are equivalent (however, in
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practice, comparison of U-labels requires first verifying that
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they actually are U-labels and not just Unicode strings). A pair
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of A-labels MUST be compared as case-insensitive ASCII (as with
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all comparisons of ASCII DNS labels). U-labels MUST be compared
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as-is, without case folding or other intermediate steps. While
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it is not necessary to validate labels in order to compare them,
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successful comparison does not imply validity. In many cases,
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not limited to comparison, validation may be important for other
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reasons and SHOULD be performed.
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3. Labels being registered MUST conform to the requirements of
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Section 4. Labels being looked up and the lookup process MUST
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conform to the requirements of Section 5.
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3.2. Applicability
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IDNA applies to all domain names in all domain name slots in
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protocols except where it is explicitly excluded. It does not apply
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to domain name slots that do not use the LDH syntax rules as
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described in the Definitions document [RFC5890].
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Because it uses the DNS, IDNA applies to many protocols that were
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specified before it was designed. IDNs occupying domain name slots
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in those older protocols MUST be in A-label form until and unless
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those protocols and their implementations are explicitly upgraded to
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be aware of IDNs and to accept the U-label form. IDNs actually
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appearing in DNS queries or responses MUST be A-labels.
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IDNA-aware protocols and implementations MAY accept U-labels,
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A-labels, or both as those particular protocols specify. IDNA is not
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defined for extended label types (see RFC 2671 [RFC2671], Section 3).
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3.2.1. DNS Resource Records
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IDNA applies only to domain names in the NAME and RDATA fields of DNS
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resource records whose CLASS is IN. See the DNS specification
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[RFC1035] for precise definitions of these terms.
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The application of IDNA to DNS resource records depends entirely on
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the CLASS of the record, and not on the TYPE except as noted below.
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This will remain true, even as new TYPEs are defined, unless a new
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TYPE defines TYPE-specific rules. Special naming conventions for SRV
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records (and "underscore labels" more generally) are incompatible
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with IDNA coding as discussed in the Definitions document [RFC5890],
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especially Section 2.3.2.3. Of course, underscore labels may be part
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of a domain that uses IDN labels at higher levels in the tree.
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3.2.2. Non-Domain-Name Data Types Stored in the DNS
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Although IDNA enables the representation of non-ASCII characters in
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domain names, that does not imply that IDNA enables the
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representation of non-ASCII characters in other data types that are
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stored in domain names, specifically in the RDATA field for types
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that have structured RDATA format. For example, an email address
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local part is stored in a domain name in the RNAME field as part of
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the RDATA of an SOA record (e.g., hostmaster@example.com would be
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represented as hostmaster.example.com). IDNA does not update the
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existing email standards, which allow only ASCII characters in local
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parts. Even though work is in progress to define
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internationalization for email addresses [RFC4952], changes to the
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email address part of the SOA RDATA would require action in, or
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updates to, other standards, specifically those that specify the
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format of the SOA RR.
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4. Registration Protocol
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This section defines the model for registering an IDN. The model is
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implementation independent; any sequence of steps that produces
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exactly the same result for all labels is considered a valid
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implementation.
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Note that, while the registration (this section) and lookup protocols
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(Section 5) are very similar in most respects, they are not
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identical, and implementers should carefully follow the steps
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described in this specification.
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4.1. Input to IDNA Registration
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Registration processes, especially processing by entities (often
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called "registrars") who deal with registrants before the request
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actually reaches the zone manager ("registry") are outside the scope
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of this definition and may differ significantly depending on local
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needs. By the time a string enters the IDNA registration process as
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described in this specification, it MUST be in Unicode and in
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Normalization Form C (NFC [Unicode-UAX15]). Entities responsible for
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zone files ("registries") MUST accept only the exact string for which
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registration is requested, free of any mappings or local adjustments.
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They MAY accept that input in any of three forms:
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1. As a pair of A-label and U-label.
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2. As an A-label only.
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3. As a U-label only.
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The first two of these forms are RECOMMENDED because the use of
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A-labels avoids any possibility of ambiguity. The first is normally
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preferred over the second because it permits further verification of
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user intent (see Section 4.2.1).
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4.2. Permitted Character and Label Validation
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4.2.1. Input Format
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If both the U-label and A-label forms are available, the registry
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MUST ensure that the A-label form is in lowercase, perform a
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conversion to a U-label, perform the steps and tests described below
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on that U-label, and then verify that the A-label produced by the
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step in Section 4.4 matches the one provided as input. In addition,
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the U-label that was provided as input and the one obtained by
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conversion of the A-label MUST match exactly. If, for some reason,
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these tests fail, the registration MUST be rejected.
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If only an A-label was provided and the conversion to a U-label is
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not performed, the registry MUST still verify that the A-label is
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superficially valid, i.e., that it does not violate any of the rules
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of Punycode encoding [RFC3492] such as the prohibition on trailing
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hyphen-minus, the requirement that all characters be ASCII, and so
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on. Strings that appear to be A-labels (e.g., they start with
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"xn--") and strings that are supplied to the registry in a context
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reserved for A-labels (such as a field in a form to be filled out),
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but that are not valid A-labels as described in this paragraph, MUST
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NOT be placed in DNS zones that support IDNA.
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If only an A-label is provided, the conversion to a U-label is not
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performed, but the superficial tests described in the previous
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paragraph are performed, registration procedures MAY, and usually
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will, bypass the tests and actions in the balance of Section 4.2 and
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in Sections 4.3 and 4.4.
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4.2.2. Rejection of Characters That Are Not Permitted
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The candidate Unicode string MUST NOT contain characters that appear
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in the "DISALLOWED" and "UNASSIGNED" lists specified in the Tables
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document [RFC5892].
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4.2.3. Label Validation
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The proposed label (in the form of a Unicode string, i.e., a string
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that at least superficially appears to be a U-label) is then examined
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+
using tests that require examination of more than one character.
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Character order is considered to be the on-the-wire order. That
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order may not be the same as the display order.
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+
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4.2.3.1. Hyphen Restrictions
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The Unicode string MUST NOT contain "--" (two consecutive hyphens) in
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+
the third and fourth character positions and MUST NOT start or end
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+
with a "-" (hyphen).
424
+
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+
4.2.3.2. Leading Combining Marks
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The Unicode string MUST NOT begin with a combining mark or combining
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character (see The Unicode Standard, Section 2.11 [Unicode] for an
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+
exact definition).
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4.2.3.3. Contextual Rules
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The Unicode string MUST NOT contain any characters whose validity is
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+
context-dependent, unless the validity is positively confirmed by a
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+
contextual rule. To check this, each code point identified as
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CONTEXTJ or CONTEXTO in the Tables document [RFC5892] MUST have a
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non-null rule. If such a code point is missing a rule, the label is
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invalid. If the rule exists but the result of applying the rule is
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negative or inconclusive, the proposed label is invalid.
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4.2.3.4. Labels Containing Characters Written Right to Left
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If the proposed label contains any characters from scripts that are
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written from right to left, it MUST meet the Bidi criteria [RFC5893].
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4.2.4. Registration Validation Requirements
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Strings that contain at least one non-ASCII character, have been
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produced by the steps above, whose contents pass all of the tests in
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+
Section 4.2.3, and are 63 or fewer characters long in
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+
ASCII-compatible encoding (ACE) form (see Section 4.4), are U-labels.
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+
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+
To summarize, tests are made in Section 4.2 for invalid characters,
463
+
invalid combinations of characters, for labels that are invalid even
464
+
if the characters they contain are valid individually, and for labels
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+
that do not conform to the restrictions for strings containing
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+
right-to-left characters.
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+
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+
4.3. Registry Restrictions
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+
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+
In addition to the rules and tests above, there are many reasons why
471
+
a registry could reject a label. Registries at all levels of the
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+
DNS, not just the top level, are expected to establish policies about
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+
label registrations. Policies are likely to be informed by the local
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+
languages and the scripts that are used to write them and may depend
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+
on many factors including what characters are in the label (for
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+
example, a label may be rejected based on other labels already
477
+
registered). See the Rationale document [RFC5894], Section 3.2, for
478
+
further discussion and recommendations about registry policies.
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480
+
The string produced by the steps in Section 4.2 is checked and
481
+
processed as appropriate to local registry restrictions. Application
482
+
of those registry restrictions may result in the rejection of some
483
+
labels or the application of special restrictions to others.
484
+
485
+
4.4. Punycode Conversion
486
+
487
+
The resulting U-label is converted to an A-label (defined in Section
488
+
2.3.2.1 of the Definitions document [RFC5890]). The A-label is the
489
+
encoding of the U-label according to the Punycode algorithm [RFC3492]
490
+
with the ACE prefix "xn--" added at the beginning of the string. The
491
+
resulting string must, of course, conform to the length limits
492
+
imposed by the DNS. This document does not update or alter the
493
+
Punycode algorithm specified in RFC 3492 in any way. RFC 3492 does
494
+
make a non-normative reference to the information about the value and
495
+
construction of the ACE prefix that appears in RFC 3490 or Nameprep
496
+
[RFC3491]. For consistency and reader convenience, IDNA2008
497
+
effectively updates that reference to point to this document. That
498
+
change does not alter the prefix itself. The prefix, "xn--", is the
499
+
same in both sets of documents.
500
+
501
+
502
+
503
+
504
+
505
+
506
+
Klensin Standards Track [Page 9]
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+
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+
RFC 5891 IDNA2008 Protocol August 2010
509
+
510
+
511
+
With the exception of the maximum string length test on Punycode
512
+
output, the failure conditions identified in the Punycode encoding
513
+
procedure cannot occur if the input is a U-label as determined by the
514
+
steps in Sections 4.1 through 4.3 above.
515
+
516
+
4.5. Insertion in the Zone
517
+
518
+
The label is registered in the DNS by inserting the A-label into a
519
+
zone.
520
+
521
+
5. Domain Name Lookup Protocol
522
+
523
+
Lookup is different from registration and different tests are applied
524
+
on the client. Although some validity checks are necessary to avoid
525
+
serious problems with the protocol, the lookup-side tests are more
526
+
permissive and rely on the assumption that names that are present in
527
+
the DNS are valid. That assumption is, however, a weak one because
528
+
the presence of wildcards in the DNS might cause a string that is not
529
+
actually registered in the DNS to be successfully looked up.
530
+
531
+
5.1. Label String Input
532
+
533
+
The user supplies a string in the local character set, for example,
534
+
by typing it, clicking on it, or copying and pasting it from a
535
+
resource identifier, e.g., a Uniform Resource Identifier (URI)
536
+
[RFC3986] or an Internationalized Resource Identifier (IRI)
537
+
[RFC3987], from which the domain name is extracted. Alternately,
538
+
some process not directly involving the user may read the string from
539
+
a file or obtain it in some other way. Processing in this step and
540
+
the one specified in Section 5.2 are local matters, to be
541
+
accomplished prior to actual invocation of IDNA.
542
+
543
+
5.2. Conversion to Unicode
544
+
545
+
The string is converted from the local character set into Unicode, if
546
+
it is not already in Unicode. Depending on local needs, this
547
+
conversion may involve mapping some characters into other characters
548
+
as well as coding conversions. Those issues are discussed in the
549
+
mapping-related sections (Sections 4.2, 4.4, 6, and 7.3) of the
550
+
Rationale document [RFC5894] and in the separate Mapping document
551
+
[IDNA2008-Mapping]. The result MUST be a Unicode string in NFC form.
552
+
553
+
5.3. A-label Input
554
+
555
+
If the input to this procedure appears to be an A-label (i.e., it
556
+
starts in "xn--", interpreted case-insensitively), the lookup
557
+
application MAY attempt to convert it to a U-label, first ensuring
558
+
that the A-label is entirely in lowercase (converting it to lowercase
559
+
560
+
561
+
562
+
Klensin Standards Track [Page 10]
563
+
564
+
RFC 5891 IDNA2008 Protocol August 2010
565
+
566
+
567
+
if necessary), and apply the tests of Section 5.4 and the conversion
568
+
of Section 5.5 to that form. If the label is converted to Unicode
569
+
(i.e., to U-label form) using the Punycode decoding algorithm, then
570
+
the processing specified in those two sections MUST be performed, and
571
+
the label MUST be rejected if the resulting label is not identical to
572
+
the original. See Section 8.1 of the Rationale document [RFC5894]
573
+
for additional discussion on this topic.
574
+
575
+
Conversion from the A-label and testing that the result is a U-label
576
+
SHOULD be performed if the domain name will later be presented to the
577
+
user in native character form (this requires that the lookup
578
+
application be IDNA-aware). If those steps are not performed, the
579
+
lookup process SHOULD at least test to determine that the string is
580
+
actually an A-label, examining it for the invalid formats specified
581
+
in the Punycode decoding specification. Applications that are not
582
+
IDNA-aware will obviously omit that testing; others MAY treat the
583
+
string as opaque to avoid the additional processing at the expense of
584
+
providing less protection and information to users.
585
+
586
+
5.4. Validation and Character List Testing
587
+
588
+
As with the registration procedure described in Section 4, the
589
+
Unicode string is checked to verify that all characters that appear
590
+
in it are valid as input to IDNA lookup processing. As discussed
591
+
above and in the Rationale document [RFC5894], the lookup check is
592
+
more liberal than the registration one. Labels that have not been
593
+
fully evaluated for conformance to the applicable rules are referred
594
+
to as "putative" labels as discussed in Section 2.3.2.1 of the
595
+
Definitions document [RFC5890]. Putative U-labels with any of the
596
+
following characteristics MUST be rejected prior to DNS lookup:
597
+
598
+
o Labels that are not in NFC [Unicode-UAX15].
599
+
600
+
o Labels containing "--" (two consecutive hyphens) in the third and
601
+
fourth character positions.
602
+
603
+
o Labels whose first character is a combining mark (see The Unicode
604
+
Standard, Section 2.11 [Unicode]).
605
+
606
+
o Labels containing prohibited code points, i.e., those that are
607
+
assigned to the "DISALLOWED" category of the Tables document
608
+
[RFC5892].
609
+
610
+
o Labels containing code points that are identified in the Tables
611
+
document as "CONTEXTJ", i.e., requiring exceptional contextual
612
+
rule processing on lookup, but that do not conform to those rules.
613
+
Note that this implies that a rule must be defined, not null: a
614
+
615
+
616
+
617
+
618
+
Klensin Standards Track [Page 11]
619
+
620
+
RFC 5891 IDNA2008 Protocol August 2010
621
+
622
+
623
+
character that requires a contextual rule but for which the rule
624
+
is null is treated in this step as having failed to conform to the
625
+
rule.
626
+
627
+
o Labels containing code points that are identified in the Tables
628
+
document as "CONTEXTO", but for which no such rule appears in the
629
+
table of rules. Applications resolving DNS names or carrying out
630
+
equivalent operations are not required to test contextual rules
631
+
for "CONTEXTO" characters, only to verify that a rule is defined
632
+
(although they MAY make such tests to provide better protection or
633
+
give better information to the user).
634
+
635
+
o Labels containing code points that are unassigned in the version
636
+
of Unicode being used by the application, i.e., in the UNASSIGNED
637
+
category of the Tables document.
638
+
639
+
This requirement means that the application must use a list of
640
+
unassigned characters that is matched to the version of Unicode
641
+
that is being used for the other requirements in this section. It
642
+
is not required that the application know which version of Unicode
643
+
is being used; that information might be part of the operating
644
+
environment in which the application is running.
645
+
646
+
In addition, the application SHOULD apply the following test.
647
+
648
+
o Verification that the string is compliant with the requirements
649
+
for right-to-left characters specified in the Bidi document
650
+
[RFC5893].
651
+
652
+
This test may be omitted in special circumstances, such as when the
653
+
lookup application knows that the conditions are enforced elsewhere,
654
+
because an attempt to look up and resolve such strings will almost
655
+
certainly lead to a DNS lookup failure except when wildcards are
656
+
present in the zone. However, applying the test is likely to give
657
+
much better information about the reason for a lookup failure --
658
+
information that may be usefully passed to the user when that is
659
+
feasible -- than DNS resolution failure information alone.
660
+
661
+
For all other strings, the lookup application MUST rely on the
662
+
presence or absence of labels in the DNS to determine the validity of
663
+
those labels and the validity of the characters they contain. If
664
+
they are registered, they are presumed to be valid; if they are not,
665
+
their possible validity is not relevant. While a lookup application
666
+
may reasonably issue warnings about strings it believes may be
667
+
problematic, applications that decline to process a string that
668
+
conforms to the rules above (i.e., does not look it up in the DNS)
669
+
are not in conformance with this protocol.
670
+
671
+
672
+
673
+
674
+
Klensin Standards Track [Page 12]
675
+
676
+
RFC 5891 IDNA2008 Protocol August 2010
677
+
678
+
679
+
5.5. Punycode Conversion
680
+
681
+
The string that has now been validated for lookup is converted to ACE
682
+
form by applying the Punycode algorithm to the string and then adding
683
+
the ACE prefix ("xn--").
684
+
685
+
5.6. DNS Name Resolution
686
+
687
+
The A-label resulting from the conversion in Section 5.5 or supplied
688
+
directly (see Section 5.3) is combined with other labels as needed to
689
+
form a fully-qualified domain name that is then looked up in the DNS,
690
+
using normal DNS resolver procedures. The lookup can obviously
691
+
either succeed (returning information) or fail.
692
+
693
+
6. Security Considerations
694
+
695
+
Security Considerations for this version of IDNA are described in the
696
+
Definitions document [RFC5890], except for the special issues
697
+
associated with right-to-left scripts and characters. The latter are
698
+
discussed in the Bidi document [RFC5893].
699
+
700
+
In order to avoid intentional or accidental attacks from labels that
701
+
might be confused with others, special problems in rendering, and so
702
+
on, the IDNA model requires that registries exercise care and
703
+
thoughtfulness about what labels they choose to permit. That issue
704
+
is discussed in Section 4.3 of this document which, in turn, points
705
+
to a somewhat more extensive discussion in the Rationale document
706
+
[RFC5894].
707
+
708
+
7. IANA Considerations
709
+
710
+
IANA actions for this version of IDNA are specified in the Tables
711
+
document [RFC5892] and discussed informally in the Rationale document
712
+
[RFC5894]. The components of IDNA described in this document do not
713
+
require any IANA actions.
714
+
715
+
8. Contributors
716
+
717
+
While the listed editor held the pen, the original versions of this
718
+
document represent the joint work and conclusions of an ad hoc design
719
+
team consisting of the editor and, in alphabetic order, Harald
720
+
Alvestrand, Tina Dam, Patrik Faltstrom, and Cary Karp. This document
721
+
draws significantly on the original version of IDNA [RFC3490] both
722
+
conceptually and for specific text. This second-generation version
723
+
would not have been possible without the work that went into that
724
+
first version and especially the contributions of its authors Patrik
725
+
Faltstrom, Paul Hoffman, and Adam Costello. While Faltstrom was
726
+
727
+
728
+
729
+
730
+
Klensin Standards Track [Page 13]
731
+
732
+
RFC 5891 IDNA2008 Protocol August 2010
733
+
734
+
735
+
actively involved in the creation of this version, Hoffman and
736
+
Costello were not and should not be held responsible for any errors
737
+
or omissions.
738
+
739
+
9. Acknowledgments
740
+
741
+
This revision to IDNA would have been impossible without the
742
+
accumulated experience since RFC 3490 was published and resulting
743
+
comments and complaints of many people in the IETF, ICANN, and other
744
+
communities (too many people to list here). Nor would it have been
745
+
possible without RFC 3490 itself and the efforts of the Working Group
746
+
that defined it. Those people whose contributions are acknowledged
747
+
in RFC 3490, RFC 4690 [RFC4690], and the Rationale document [RFC5894]
748
+
were particularly important.
749
+
750
+
Specific textual changes were incorporated into this document after
751
+
suggestions from the other contributors, Stephane Bortzmeyer, Vint
752
+
Cerf, Lisa Dusseault, Paul Hoffman, Kent Karlsson, James Mitchell,
753
+
Erik van der Poel, Marcos Sanz, Andrew Sullivan, Wil Tan, Ken
754
+
Whistler, Chris Wright, and other WG participants and reviewers
755
+
including Martin Duerst, James Mitchell, Subramanian Moonesamy, Peter
756
+
Saint-Andre, Margaret Wasserman, and Dan Winship who caught specific
757
+
errors and recommended corrections. Special thanks are due to Paul
758
+
Hoffman for permission to extract material to form the basis for
759
+
Appendix A from a draft document that he prepared.
760
+
761
+
10. References
762
+
763
+
10.1. Normative References
764
+
765
+
[RFC1034] Mockapetris, P., "Domain names - concepts and
766
+
facilities", STD 13, RFC 1034, November 1987.
767
+
768
+
[RFC1035] Mockapetris, P., "Domain names - implementation and
769
+
specification", STD 13, RFC 1035, November 1987.
770
+
771
+
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
772
+
Requirement Levels", BCP 14, RFC 2119, March 1997.
773
+
774
+
[RFC3492] Costello, A., "Punycode: A Bootstring encoding of
775
+
Unicode for Internationalized Domain Names in
776
+
Applications (IDNA)", RFC 3492, March 2003.
777
+
778
+
[RFC5890] Klensin, J., "Internationalized Domain Names for
779
+
Applications (IDNA): Definitions and Document
780
+
Framework", RFC 5890, August 2010.
781
+
782
+
783
+
784
+
785
+
786
+
Klensin Standards Track [Page 14]
787
+
788
+
RFC 5891 IDNA2008 Protocol August 2010
789
+
790
+
791
+
[RFC5892] Faltstrom, P., Ed., "The Unicode Code Points and
792
+
Internationalized Domain Names for Applications (IDNA)",
793
+
RFC 5892, August 2010.
794
+
795
+
[RFC5893] Alvestrand, H., Ed. and C. Karp, "Right-to-Left Scripts
796
+
for Internationalized Domain Names for Applications
797
+
(IDNA)", RFC 5893, August 2010.
798
+
799
+
[Unicode-UAX15]
800
+
The Unicode Consortium, "Unicode Standard Annex #15:
801
+
Unicode Normalization Forms", September 2009,
802
+
<http://www.unicode.org/reports/tr15/>.
803
+
804
+
10.2. Informative References
805
+
806
+
[ASCII] American National Standards Institute (formerly United
807
+
States of America Standards Institute), "USA Code for
808
+
Information Interchange", ANSI X3.4-1968, 1968. ANSI
809
+
X3.4-1968 has been replaced by newer versions with
810
+
slight modifications, but the 1968 version remains
811
+
definitive for the Internet.
812
+
813
+
[IDNA2008-Mapping]
814
+
Resnick, P. and P. Hoffman, "Mapping Characters in
815
+
Internationalized Domain Names for Applications (IDNA)",
816
+
Work in Progress, April 2010.
817
+
818
+
[RFC2671] Vixie, P., "Extension Mechanisms for DNS (EDNS0)",
819
+
RFC 2671, August 1999.
820
+
821
+
[RFC3490] Faltstrom, P., Hoffman, P., and A. Costello,
822
+
"Internationalizing Domain Names in Applications
823
+
(IDNA)", RFC 3490, March 2003.
824
+
825
+
[RFC3491] Hoffman, P. and M. Blanchet, "Nameprep: A Stringprep
826
+
Profile for Internationalized Domain Names (IDN)",
827
+
RFC 3491, March 2003.
828
+
829
+
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
830
+
Resource Identifier (URI): Generic Syntax", STD 66,
831
+
RFC 3986, January 2005.
832
+
833
+
[RFC3987] Duerst, M. and M. Suignard, "Internationalized Resource
834
+
Identifiers (IRIs)", RFC 3987, January 2005.
835
+
836
+
[RFC4690] Klensin, J., Faltstrom, P., Karp, C., and IAB, "Review
837
+
and Recommendations for Internationalized Domain Names
838
+
(IDNs)", RFC 4690, September 2006.
839
+
840
+
841
+
842
+
Klensin Standards Track [Page 15]
843
+
844
+
RFC 5891 IDNA2008 Protocol August 2010
845
+
846
+
847
+
[RFC4952] Klensin, J. and Y. Ko, "Overview and Framework for
848
+
Internationalized Email", RFC 4952, July 2007.
849
+
850
+
[RFC5894] Klensin, J., "Internationalized Domain Names for
851
+
Applications (IDNA): Background, Explanation, and
852
+
Rationale", RFC 5894, August 2010.
853
+
854
+
[Unicode] The Unicode Consortium, "The Unicode Standard, Version
855
+
5.0", 2007. Boston, MA, USA: Addison-Wesley. ISBN
856
+
0-321-48091-0. This printed reference has now been
857
+
updated online to reflect additional code points. For
858
+
code points, the reference at the time this document was
859
+
published is to Unicode 5.2.
860
+
861
+
862
+
863
+
864
+
865
+
866
+
867
+
868
+
869
+
870
+
871
+
872
+
873
+
874
+
875
+
876
+
877
+
878
+
879
+
880
+
881
+
882
+
883
+
884
+
885
+
886
+
887
+
888
+
889
+
890
+
891
+
892
+
893
+
894
+
895
+
896
+
897
+
898
+
Klensin Standards Track [Page 16]
899
+
900
+
RFC 5891 IDNA2008 Protocol August 2010
901
+
902
+
903
+
Appendix A. Summary of Major Changes from IDNA2003
904
+
905
+
1. Update base character set from Unicode 3.2 to Unicode version
906
+
agnostic.
907
+
908
+
2. Separate the definitions for the "registration" and "lookup"
909
+
activities.
910
+
911
+
3. Disallow symbol and punctuation characters except where special
912
+
exceptions are necessary.
913
+
914
+
4. Remove the mapping and normalization steps from the protocol and
915
+
have them, instead, done by the applications themselves,
916
+
possibly in a local fashion, before invoking the protocol.
917
+
918
+
5. Change the way that the protocol specifies which characters are
919
+
allowed in labels from "humans decide what the table of code
920
+
points contains" to "decision about code points are based on
921
+
Unicode properties plus a small exclusion list created by
922
+
humans".
923
+
924
+
6. Introduce the new concept of characters that can be used only in
925
+
specific contexts.
926
+
927
+
7. Allow typical words and names in languages such as Dhivehi and
928
+
Yiddish to be expressed.
929
+
930
+
8. Make bidirectional domain names (delimited strings of labels,
931
+
not just labels standing on their own) display in a less
932
+
surprising fashion, whether they appear in obvious domain name
933
+
contexts or as part of running text in paragraphs.
934
+
935
+
9. Remove the dot separator from the mandatory part of the
936
+
protocol.
937
+
938
+
10. Make some currently valid labels that are not actually IDNA
939
+
labels invalid.
940
+
941
+
Author's Address
942
+
943
+
John C Klensin
944
+
1770 Massachusetts Ave, Ste 322
945
+
Cambridge, MA 02140
946
+
USA
947
+
948
+
Phone: +1 617 245 1457
949
+
EMail: john+ietf@jck.com
950
+
951
+
952
+
953
+
954
+
Klensin Standards Track [Page 17]
955
+
+3923
spec/rfc5892.txt
+3923
spec/rfc5892.txt
···
1
+
2
+
3
+
4
+
5
+
6
+
7
+
Internet Engineering Task Force (IETF) P. Faltstrom, Ed.
8
+
Request for Comments: 5892 Cisco
9
+
Category: Standards Track August 2010
10
+
ISSN: 2070-1721
11
+
12
+
13
+
The Unicode Code Points and
14
+
Internationalized Domain Names for Applications (IDNA)
15
+
16
+
Abstract
17
+
18
+
This document specifies rules for deciding whether a code point,
19
+
considered in isolation or in context, is a candidate for inclusion
20
+
in an Internationalized Domain Name (IDN).
21
+
22
+
It is part of the specification of Internationalizing Domain Names in
23
+
Applications 2008 (IDNA2008).
24
+
25
+
Status of This Memo
26
+
27
+
This is an Internet Standards Track document.
28
+
29
+
This document is a product of the Internet Engineering Task Force
30
+
(IETF). It represents the consensus of the IETF community. It has
31
+
received public review and has been approved for publication by the
32
+
Internet Engineering Steering Group (IESG). Further information on
33
+
Internet Standards is available in Section 2 of RFC 5741.
34
+
35
+
Information about the current status of this document, any errata,
36
+
and how to provide feedback on it may be obtained at
37
+
http://www.rfc-editor.org/info/rfc5892.
38
+
39
+
Copyright Notice
40
+
41
+
Copyright (c) 2010 IETF Trust and the persons identified as the
42
+
document authors. All rights reserved.
43
+
44
+
This document is subject to BCP 78 and the IETF Trust's Legal
45
+
Provisions Relating to IETF Documents
46
+
(http://trustee.ietf.org/license-info) in effect on the date of
47
+
publication of this document. Please review these documents
48
+
carefully, as they describe your rights and restrictions with respect
49
+
to this document. Code Components extracted from this document must
50
+
include Simplified BSD License text as described in Section 4.e of
51
+
the Trust Legal Provisions and are provided without warranty as
52
+
described in the Simplified BSD License.
53
+
54
+
55
+
56
+
57
+
58
+
Faltstrom Standards Track [Page 1]
59
+
60
+
RFC 5892 IDNA Code Points August 2010
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Table of Contents
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
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2. Category Definitions Used to Calculate Derived Property
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Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
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2.1. LetterDigits (A) . . . . . . . . . . . . . . . . . . . . . 5
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2.2. Unstable (B) . . . . . . . . . . . . . . . . . . . . . . . 6
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2.3. IgnorableProperties (C) . . . . . . . . . . . . . . . . . 6
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2.4. IgnorableBlocks (D) . . . . . . . . . . . . . . . . . . . 7
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2.5. LDH (E) . . . . . . . . . . . . . . . . . . . . . . . . . 7
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2.6. Exceptions (F) . . . . . . . . . . . . . . . . . . . . . . 7
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2.7. BackwardCompatible (G) . . . . . . . . . . . . . . . . . . 9
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2.8. JoinControl (H) . . . . . . . . . . . . . . . . . . . . . 9
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2.9. OldHangulJamo (I) . . . . . . . . . . . . . . . . . . . . 9
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2.10. Unassigned (J) . . . . . . . . . . . . . . . . . . . . . . 9
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3. Calculation of the Derived Property . . . . . . . . . . . . . 10
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4. Code Points . . . . . . . . . . . . . . . . . . . . . . . . . 10
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5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
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5.1. IDNA-Derived Property Value Registry . . . . . . . . . . . 11
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5.2. IDNA Context Registry . . . . . . . . . . . . . . . . . . 11
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5.2.1. Template for Context Registry . . . . . . . . . . . . 11
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6. Security Considerations . . . . . . . . . . . . . . . . . . . 12
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7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
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Appendix A. Contextual Rules Registry . . . . . . . . . . . . . 13
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Appendix A.1. ZERO WIDTH NON-JOINER . . . . . . . . . . . . . . . 15
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Appendix A.2. ZERO WIDTH JOINER . . . . . . . . . . . . . . . . . 16
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Appendix A.3. MIDDLE DOT . . . . . . . . . . . . . . . . . . . . . 16
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Appendix A.4. GREEK LOWER NUMERAL SIGN (KERAIA) . . . . . . . . . 17
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Appendix A.5. HEBREW PUNCTUATION GERESH . . . . . . . . . . . . . 17
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Appendix A.6. HEBREW PUNCTUATION GERSHAYIM . . . . . . . . . . . . 18
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Appendix A.7. KATAKANA MIDDLE DOT . . . . . . . . . . . . . . . . 18
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Appendix A.8. ARABIC-INDIC DIGITS . . . . . . . . . . . . . . . . 19
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Appendix A.9. EXTENDED ARABIC-INDIC DIGITS . . . . . . . . . . . . 19
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Appendix B. Code Points 0x0000 - 0x10FFFF . . . . . . . . . . . 20
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Appendix B.1. Code Points in Unicode Character Database (UCD)
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Format . . . . . . . . . . . . . . . . . . . . . . . 20
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8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 69
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8.1. Normative References . . . . . . . . . . . . . . . . . . . 69
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8.2. Informative References . . . . . . . . . . . . . . . . . . 69
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Faltstrom Standards Track [Page 2]
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RFC 5892 IDNA Code Points August 2010
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1. Introduction
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RFC 4690 [RFC4690] suggests an inclusion-based approach for selecting
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the code points from The Unicode Standard [Unicode52] that should be
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included in the list of code points that may be used in
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Internationalized Domain Names.
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Specifically, RFC 4690 [RFC4690] says the following:
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The IAB has concluded that there is a consensus within the broader
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community that lists of code points should be specified by the use
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of an inclusion-based mechanism (i.e., identifying the characters
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that are permitted), rather than by excluding a small number of
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characters from the total Unicode set as Stringprep [RFC3454] and
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Nameprep [RFC3491] do today. That conclusion should be reviewed
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by the IETF community and action taken as appropriate.
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This document reviews and classifies the collections of code points
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in the Unicode character set by examining various properties of the
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code points. It then defines an algorithm for determining a derived
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property value. It specifies a procedure, and not a table, of code
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points so that the algorithm can be used to determine code point sets
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independent of the version of Unicode that is in use.
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This document is not intended to specify precisely how these property
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values are to be applied in IDN labels. That information appears in
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the Protocol document [RFC5891], but it is important to understand
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that the assignment of a value of this property to a particular
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character is not sufficient to determine whether it can be used in a
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given label. In particular, some combinations of allowed code points
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are not advisable for use in IDNs due to rules specific to a script
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or class of characters. The requirement for such rules is linked to
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the operations in the Protocol document and especially to the
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characters designated as requiring contextual rules.
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The value of the property is to be interpreted as follows.
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o PROTOCOL VALID: Those that are allowed to be used in IDNs. Code
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points with this property value are permitted for general use in
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IDNs. However, that a label consists only of code points that
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have this property value does not imply that the label can be used
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in DNS. See the Protocol document for algorithms to make
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decisions about labels in domain names. The abbreviated term
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PVALID is used to refer to this value in the rest of this
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document.
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RFC 5892 IDNA Code Points August 2010
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o CONTEXTUAL RULE REQUIRED: Some characteristics of the character,
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such as it being invisible in certain contexts or problematic in
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others, require that it not be used in labels unless specific
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other characters or properties are present. The abbreviated term
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CONTEXT is used to refer to this value in the rest of this
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document. There are two subdivisions of CONTEXTUAL RULE REQUIRED,
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one for Join_controls (called CONTEXTJ) and for other characters
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(called CONTEXTO). These are discussed in more detail below and
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in the Protocol document.
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o DISALLOWED: Those that should clearly not be included in IDNs.
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Code points with this property value are not permitted in IDNs.
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o UNASSIGNED: Those code points that are not designated (i.e., are
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unassigned) in the Unicode Standard.
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The mechanisms described here allow determination of the value of the
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property for future versions of Unicode (including characters added
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after Unicode 5.2). Changes in Unicode properties that do not affect
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the outcome of this process do not affect IDN. For example, a
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character can have its Unicode General_Category value (see
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[Unicode52]) change from So to Sm or from Lo to Ll, without affecting
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the algorithm results. Moreover, even if such changes were the
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result, the BackwardCompatible list (Section 2.7) can be adjusted to
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ensure the stability of the results.
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Some code points need to be allowed in exceptional circumstances but
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should be excluded in all other cases; these rules are also described
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in other documents. The most notable of these are the Join Control
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characters, U+200D ZERO WIDTH JOINER and U+200C ZERO WIDTH
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NON-JOINER. Both of them have the derived property value CONTEXTJ.
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A character with the derived property value CONTEXTJ or CONTEXTO
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(CONTEXTUAL RULE REQUIRED) is not to be used unless an appropriate
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rule has been established and the context of the character is
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consistent with that rule. It is invalid to either register a string
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containing these characters or even to look one up unless such a
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contextual rule is found and satisfied. Please see Appendix A, "The
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Contextual Rules Registry", for more information.
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This document is part of a series that, together, constitute a
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proposal for updating the IDNA standards to resolve issues uncovered
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in recent years, cover a broader range of scripts, and provide for
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migration to newer versions of Unicode. See the Rationale document
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[RFC5894] for a broader discussion.
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The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
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"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
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document are to be interpreted as described in RFC 2119 [RFC2119].
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Faltstrom Standards Track [Page 4]
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RFC 5892 IDNA Code Points August 2010
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2. Category Definitions Used to Calculate Derived Property Value
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The derived property obtains its value based on a two-step procedure.
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First, characters are placed in one or more character categories
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based on either core properties defined by the Unicode Standard or by
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treating the code point as an exception and addressing the code point
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by its code point value. These categories are not mutually
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exclusive.
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In the second step, set operations are used with these categories to
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determine the values for an IDN-specific property. Those operations
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are specified in Section 3.
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Unicode property names and property value names may have short
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abbreviations, such as gc for the General_Category property, and Ll
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for the Lowercase_Letter property value of the gc property.
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In the following specification of categories, the operation that
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returns the value of a particular Unicode character property for a
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code point is designated by using the formal name of that property
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(from PropertyAliases.txt) followed by '(cp)'. For example, the
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value of the General_Category property for a code point is indicated
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by General_Category(cp).
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2.1. LetterDigits (A)
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A: General_Category(cp) is in {Ll, Lu, Lo, Nd, Lm, Mn, Mc}
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These rules identify characters commonly used in mnemonics and often
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informally described as "language characters". In general, only code
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points assigned to this category are suitable for use in IDN.
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For more information, see Section 4.5 of The Unicode Standard
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[Unicode].
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The categories used in this rule are:
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o Ll - Lowercase_Letter
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o Lu - Uppercase_Letter
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o Lo - Other_Letter
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o Nd - Decimal_Number
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o Lm - Modifier_Letter
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o Mn - Nonspacing_Mark
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o Mc - Spacing_Mark
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2.2. Unstable (B)
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B: toNFKC(toCaseFold(toNFKC(cp))) != cp
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This category is used to group the characters that are not stable
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under Normalization Form K (NFKC) and case folding. In general,
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these code points are not suitable for use for IDN.
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The toCaseFold() operation is defined in Section 3.13 of The Unicode
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Standard [Unicode].
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The toNFKC() operation returns the code point in normalization form
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KC. For more information, see Section 5 of Unicode Standard Annex
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#15 [TR15].
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It should be noted that NFKC is used, although Normalization Form C
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(NFC) is used in the "IDNA Protocol" document [RFC5891].
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2.3. IgnorableProperties (C)
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C: Default_Ignorable_Code_Point(cp) = True or
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White_Space(cp) = True or
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Noncharacter_Code_Point(cp) = True
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This category is used to group code points that are not recommended
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for use in identifiers. In general, these code points are not
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suitable for use in an IDN.
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The definition for Default_Ignorable_Code_Point can be found in
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DerivedCoreProperties.txt [DerivedCoreProperties] and is at the time
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of Unicode 5.2:
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Other_Default_Ignorable_Code_Point + Cf (Format characters)
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+ Variation_Selector - White_Space - FFF9..FFFB (Annotation
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Characters) - 0600..0603, 06DD, 070F (exceptional Cf characters
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that should be visible)
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2.4. IgnorableBlocks (D)
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D: Block(cp) is in {Combining Diacritical Marks for Symbols,
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Musical Symbols, Ancient Greek Musical Notation}
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This category is used to identify code points that are not useful in
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mnemonics or that are otherwise impractical for IDN use. In general,
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these code points are not suitable for use for IDN.
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The definition of blocks can be found in Blocks.txt [BlockNames].
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2.5. LDH (E)
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E: cp is in {002D, 0030..0039, 0061..007A}
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This category is used in the second step to preserve the traditional
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"hostname" (LDH -- as described in the Definitions document
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[RFC5890]) characters ('-', 0-9, and a-z). In general, these code
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points are suitable for use for IDN. Note that there are other rules
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regarding the code point U+002D HYPHEN-MINUS that are specified in
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the IDNA Protocol Specification [RFC5891].
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2.6. Exceptions (F)
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F: cp is in {00B7, 00DF, 0375, 03C2, 05F3, 05F4, 0640, 0660,
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0661, 0662, 0663, 0664, 0665, 0666, 0667, 0668,
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0669, 06F0, 06F1, 06F2, 06F3, 06F4, 06F5, 06F6,
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06F7, 06F8, 06F9, 06FD, 06FE, 07FA, 0F0B, 3007,
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302E, 302F, 3031, 3032, 3033, 3034, 3035, 303B,
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30FB}
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This category explicitly lists code points for which the category
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cannot be assigned using only the core property values that exist in
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the Unicode standard. The values are according to the table below:
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PVALID -- Would otherwise have been DISALLOWED
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00DF; PVALID # LATIN SMALL LETTER SHARP S
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03C2; PVALID # GREEK SMALL LETTER FINAL SIGMA
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06FD; PVALID # ARABIC SIGN SINDHI AMPERSAND
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06FE; PVALID # ARABIC SIGN SINDHI POSTPOSITION MEN
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0F0B; PVALID # TIBETAN MARK INTERSYLLABIC TSHEG
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3007; PVALID # IDEOGRAPHIC NUMBER ZERO
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388
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CONTEXTO -- Would otherwise have been DISALLOWED
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401
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00B7; CONTEXTO # MIDDLE DOT
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0375; CONTEXTO # GREEK LOWER NUMERAL SIGN (KERAIA)
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05F3; CONTEXTO # HEBREW PUNCTUATION GERESH
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05F4; CONTEXTO # HEBREW PUNCTUATION GERSHAYIM
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30FB; CONTEXTO # KATAKANA MIDDLE DOT
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CONTEXTO -- Would otherwise have been PVALID
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0660; CONTEXTO # ARABIC-INDIC DIGIT ZERO
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0661; CONTEXTO # ARABIC-INDIC DIGIT ONE
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0662; CONTEXTO # ARABIC-INDIC DIGIT TWO
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0663; CONTEXTO # ARABIC-INDIC DIGIT THREE
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0664; CONTEXTO # ARABIC-INDIC DIGIT FOUR
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0665; CONTEXTO # ARABIC-INDIC DIGIT FIVE
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0666; CONTEXTO # ARABIC-INDIC DIGIT SIX
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0667; CONTEXTO # ARABIC-INDIC DIGIT SEVEN
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0668; CONTEXTO # ARABIC-INDIC DIGIT EIGHT
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0669; CONTEXTO # ARABIC-INDIC DIGIT NINE
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06F0; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT ZERO
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06F1; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT ONE
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06F2; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT TWO
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06F3; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT THREE
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06F4; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT FOUR
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06F5; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT FIVE
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06F6; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT SIX
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06F7; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT SEVEN
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06F8; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT EIGHT
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06F9; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT NINE
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+
430
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DISALLOWED -- Would otherwise have been PVALID
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+
432
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0640; DISALLOWED # ARABIC TATWEEL
433
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07FA; DISALLOWED # NKO LAJANYALAN
434
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302E; DISALLOWED # HANGUL SINGLE DOT TONE MARK
435
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302F; DISALLOWED # HANGUL DOUBLE DOT TONE MARK
436
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3031; DISALLOWED # VERTICAL KANA REPEAT MARK
437
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3032; DISALLOWED # VERTICAL KANA REPEAT WITH VOICED SOUND MARK
438
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3033; DISALLOWED # VERTICAL KANA REPEAT MARK UPPER HALF
439
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3034; DISALLOWED # VERTICAL KANA REPEAT WITH VOICED SOUND MARK UPPER HA
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3035; DISALLOWED # VERTICAL KANA REPEAT MARK LOWER HALF
441
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303B; DISALLOWED # VERTICAL IDEOGRAPHIC ITERATION MARK
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+
443
+
444
+
445
+
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2.7. BackwardCompatible (G)
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G: cp is in {}
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459
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This category includes the code points that property values in
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versions of Unicode after 5.2 have changed in such a way that the
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derived property value would no longer be PVALID or DISALLOWED. If
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changes are made to future versions of Unicode so that code points
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might change the property value from PVALID or DISALLOWED, then this
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table can be updated and keep special exception values so that the
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property values for code points stay stable.
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2.8. JoinControl (H)
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H: Join_Control(cp) = True
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+
471
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This category consists of Join Control characters (i.e., they are not
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in LetterDigits (Section 2.1) but are still required in IDN labels
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under some circumstances).
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+
475
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2.9. OldHangulJamo (I)
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I: Hangul_Syllable_Type(cp) is in {L, V, T}
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+
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This category consists of all conjoining Hangul Jamo (Leading Jamo,
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Vowel Jamo, and Trailing Jamo).
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Elimination of conjoining Hangul Jamo from the set of PVALID
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characters results in restricting the set of Korean PVALID characters
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just to preformed, modern Hangul syllable characters. Old Hangul
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syllables, which must be spelled with sequences of conjoining Hangul
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Jamo, are not PVALID for IDNs.
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2.10. Unassigned (J)
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J: General_Category(cp) is in {Cn} and
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Noncharacter_Code_Point(cp) = False
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+
493
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This category consists of code points in the Unicode character set
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that are not (yet) assigned. It should be noted that Unicode
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distinguishes between "unassigned code points" and "unassigned
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characters". The unassigned code points are all but (Cn -
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Noncharacters), while the unassigned *characters* are all but (Cn +
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Cs).
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RFC 5892 IDNA Code Points August 2010
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3. Calculation of the Derived Property
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As described above (Section 1) and in more detail in the IDNA
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Protocol document [RFC5891], possible values of the IDN property are:
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o PVALID
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+
518
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o CONTEXTJ
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+
520
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o CONTEXTO
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+
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o DISALLOWED
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+
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o UNASSIGNED
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+
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The algorithm to calculate the value of the derived property is as
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follows. If the name of a rule (such as Exception) is used, that
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implies the set of code points that the rule defines, while the same
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name as a function call (such as Exception(cp)) implies the value cp
530
+
has in the Exceptions table.
531
+
532
+
If .cp. .in. Exceptions Then Exceptions(cp);
533
+
Else If .cp. .in. BackwardCompatible Then BackwardCompatible(cp);
534
+
Else If .cp. .in. Unassigned Then UNASSIGNED;
535
+
Else If .cp. .in. LDH Then PVALID;
536
+
Else If .cp. .in. JoinControl Then CONTEXTJ;
537
+
Else If .cp. .in. Unstable Then DISALLOWED;
538
+
Else If .cp. .in. IgnorableProperties Then DISALLOWED;
539
+
Else If .cp. .in. IgnorableBlocks Then DISALLOWED;
540
+
Else If .cp. .in. OldHangulJamo Then DISALLOWED;
541
+
Else If .cp. .in. LetterDigits Then PVALID;
542
+
Else DISALLOWED;
543
+
544
+
4. Code Points
545
+
546
+
The categories and rules defined in Sections 2 and 3 apply to all
547
+
Unicode code points. The table in Appendix B shows, for illustrative
548
+
purposes, the consequences of the categories and classification
549
+
rules, and the resulting property values.
550
+
551
+
The list of code points that can be found in Appendix B is
552
+
non-normative. Sections 2 and 3 are normative.
553
+
554
+
555
+
556
+
557
+
558
+
559
+
560
+
561
+
562
+
Faltstrom Standards Track [Page 10]
563
+
564
+
RFC 5892 IDNA Code Points August 2010
565
+
566
+
567
+
5. IANA Considerations
568
+
569
+
5.1. IDNA-Derived Property Value Registry
570
+
571
+
IANA has created a registry with the derived properties for the
572
+
versions of Unicode released after (and including) version 5.2. The
573
+
derived property value is to be calculated in cooperation with a
574
+
designated expert [RFC5226] according to the specifications in
575
+
Sections 2 and 3 and not by copying the non-normative table found in
576
+
Appendix B.
577
+
578
+
If non-backward-compatible changes or other problems arise during the
579
+
creation or designated expert review of the table of derived property
580
+
values, they should be flagged for the IESG. Changes to the rules
581
+
(as specified in Sections 2 and 3), including BackwardCompatible
582
+
(Section 2.7) (a set that is at release of this document is empty)
583
+
require IETF Review, as described in RFC 5226 [RFC5226].
584
+
585
+
5.2. IDNA Context Registry
586
+
587
+
For characters that are defined in the IDNA derived property value
588
+
registry (Section 5.1) as CONTEXTO or CONTEXTJ and that therefore
589
+
require a contextual rule, IANA has created and now maintains a list
590
+
of approved contextual rules. Additions or changes to these rules
591
+
require IETF Review, as described in [RFC5226].
592
+
593
+
Appendix A contains further discussion and a table from which that
594
+
registry can be initialized.
595
+
596
+
5.2.1. Template for Context Registry
597
+
598
+
The following information is to be given when a new rule is created.
599
+
600
+
Name: Unique name of the rule
601
+
602
+
Code point: Rule that should be applied when this code point
603
+
exists in the label
604
+
605
+
Overview: Description in plain English on what the rule verifies
606
+
607
+
Lookup: Should the rule be applied at time of lookup?
608
+
609
+
Rule Set: The set of rules, with a reference to the defining
610
+
document.
611
+
612
+
613
+
614
+
615
+
616
+
617
+
618
+
Faltstrom Standards Track [Page 11]
619
+
620
+
RFC 5892 IDNA Code Points August 2010
621
+
622
+
623
+
6. Security Considerations
624
+
625
+
Security Considerations for this version of IDNA, except for the
626
+
special issues associated with right-to-left scripts and characters,
627
+
are described in the Definitions document [RFC5890]. Specific issues
628
+
for labels containing characters associated with scripts written
629
+
right to left appear in the Bidi document [RFC5893].
630
+
631
+
7. Acknowledgements
632
+
633
+
This document would not have been possible to produce without input
634
+
from many people. The main contributors are (in alphabetical order)
635
+
Harald Alvestrand, Vint Cerf, Tina Dam, Mark Davis, Gihan Dias,
636
+
Mouhammet Diop, Michael Everson, Asmus Freytag, Debbie Garside, Paul
637
+
Hoffman, Kent Karlsson, Cary Karp, Jaeyoun Kim, John Klensin, Olaf
638
+
Kolkman, Gervase Markham, Ram Mohan, Lisa Moore, Yngve Pettersen,
639
+
Erik van der Poel, Hualin Qian, Rick Reed, Pete Resnick, Lakmal
640
+
Silva, Michel Suignard, Andrew Sullivan, Wil Tan, Kenneth Whistler,
641
+
Chris Wright, and Yoshiro Yoneya.
642
+
643
+
644
+
645
+
646
+
647
+
648
+
649
+
650
+
651
+
652
+
653
+
654
+
655
+
656
+
657
+
658
+
659
+
660
+
661
+
662
+
663
+
664
+
665
+
666
+
667
+
668
+
669
+
670
+
671
+
672
+
673
+
674
+
Faltstrom Standards Track [Page 12]
675
+
676
+
RFC 5892 IDNA Code Points August 2010
677
+
678
+
679
+
Appendix A. Contextual Rules Registry
680
+
681
+
As discussed in Section 5.2 and in the IANA Considerations section of
682
+
the Rationale document [RFC5894], a registry of rules that define the
683
+
contexts in which particular PROTOCOL-VALID characters, characters
684
+
associated with a requirement for Contextual Information, are
685
+
permitted. These rules are expressed as tests on the label in which
686
+
the characters appear (all, or any part of, the label may be tested).
687
+
688
+
The grammatical rules are expressed in pseudo-code. The conventions
689
+
used for that pseudo-code are explained here.
690
+
691
+
Each rule is constructed as a Boolean expression that evaluates to
692
+
either True or False. A simple "True;" or "False;" rule sets the
693
+
default result value for the rule set. Subsequent conditional rules
694
+
that evaluate to True or False may re-set the result value.
695
+
696
+
A special value "Undefined" is used to deal with any error
697
+
conditions, such as an attempt to test a character before the start
698
+
of a label or after the end of a label. If any term of a rule
699
+
evaluates to Undefined, further evaluation of the rule immediately
700
+
terminates, as the result value of the rule will itself be Undefined.
701
+
702
+
cp represents the code point to be tested.
703
+
704
+
FirstChar is a special term that denotes the first code point in a
705
+
label.
706
+
707
+
LastChar is a special term that denotes the last code point in a
708
+
label.
709
+
710
+
.eq. represents the equality relation.
711
+
712
+
A .eq. B evaluates to True if A equals B.
713
+
714
+
.is. represents checking the position in a label.
715
+
716
+
A .is. B evaluates to True if A and B have same position in
717
+
the same label.
718
+
719
+
.ne. represents the non-equality relation.
720
+
721
+
A .ne. B evaluates to True if A is not equal to B.
722
+
723
+
.in. represents the set inclusion relation.
724
+
725
+
A .in. B evaluates to True if A is a member of the set B.
726
+
727
+
728
+
729
+
730
+
Faltstrom Standards Track [Page 13]
731
+
732
+
RFC 5892 IDNA Code Points August 2010
733
+
734
+
735
+
A functional notation, Function_Name(cp), is used to express either
736
+
string positions within a label, Boolean character property tests of
737
+
a code point, or a regular expression match. When such function
738
+
names refer to Boolean character property tests, the function names
739
+
use the exact Unicode character property name for the property in
740
+
question, and "cp" is evaluated as the Unicode value of the code
741
+
point to be tested, rather than as its position in the label. When
742
+
such function names refer to string positions within a label, "cp" is
743
+
evaluated as its position in the label.
744
+
745
+
RegExpMatch(X) takes as its parameter X a schematic regular
746
+
expression consisting of a mix of Unicode character property values
747
+
and literal Unicode code points.
748
+
749
+
Script(cp) returns the value of the Unicode Script property, as
750
+
defined in Scripts.txt in the Unicode Character Database.
751
+
752
+
Canonical_Combining_Class(cp) returns the value of the Unicode
753
+
Canonical_Combining_Class property, as defined in UnicodeData.txt in
754
+
the Unicode Character Database.
755
+
756
+
Before(cp) returns the code point of the character immediately
757
+
preceding cp in logical order in the string representing the label.
758
+
Before(FirstChar) evaluates to Undefined.
759
+
760
+
After(cp) returns the code point of the character immediately
761
+
following cp in logical order in the string representing the label.
762
+
After(LastChar) evaluates to Undefined.
763
+
764
+
Note that "Before" and "After" do not refer to the visual display
765
+
order of the character in a label, which may be reversed or otherwise
766
+
modified by the bidirectional algorithm for labels including
767
+
characters from scripts written right to left. Instead, "Before" and
768
+
"After" refer to the network order of the character in the label.
769
+
770
+
The clauses "Then True" and "Then False" imply exit from the
771
+
pseudo-code routine with the corresponding result.
772
+
773
+
Repeated evaluation for all characters in a label makes use of the
774
+
special construct:
775
+
776
+
For All Characters:
777
+
778
+
Expression;
779
+
780
+
End For;
781
+
782
+
783
+
784
+
785
+
786
+
Faltstrom Standards Track [Page 14]
787
+
788
+
RFC 5892 IDNA Code Points August 2010
789
+
790
+
791
+
This construct requires repeated evaluation of "Expression" for each
792
+
code point in the label, starting from FirstChar and proceeding to
793
+
LastChar.
794
+
795
+
The different fields in the rules are to be interpreted as follows:
796
+
797
+
Code point:
798
+
The code point, or code points, to which this rule is to be
799
+
applied. Normally, this implies that if any of the code points in
800
+
a label is as defined, then the rules should be applied. If
801
+
evaluated to True, the code point is OK as used; if evaluated to
802
+
False, it is not OK.
803
+
804
+
Overview:
805
+
A description of the goal with the rule, in plain English.
806
+
807
+
Lookup:
808
+
True if application of this rule is recommended at lookup time;
809
+
False otherwise.
810
+
811
+
Rule Set:
812
+
The rule set itself, as described above.
813
+
814
+
Appendix A.1. ZERO WIDTH NON-JOINER
815
+
816
+
Code point:
817
+
U+200C
818
+
819
+
Overview:
820
+
This may occur in a formally cursive script (such as Arabic) in a
821
+
context where it breaks a cursive connection as required for
822
+
orthographic rules, as in the Persian language, for example. It
823
+
also may occur in Indic scripts in a consonant-conjunct context
824
+
(immediately following a virama), to control required display of
825
+
such conjuncts.
826
+
827
+
Lookup:
828
+
True
829
+
830
+
Rule Set:
831
+
832
+
False;
833
+
834
+
If Canonical_Combining_Class(Before(cp)) .eq. Virama Then True;
835
+
836
+
If RegExpMatch((Joining_Type:{L,D})(Joining_Type:T)*\u200C
837
+
838
+
(Joining_Type:T)*(Joining_Type:{R,D})) Then True;
839
+
840
+
841
+
842
+
Faltstrom Standards Track [Page 15]
843
+
844
+
RFC 5892 IDNA Code Points August 2010
845
+
846
+
847
+
Appendix A.2. ZERO WIDTH JOINER
848
+
849
+
Code point:
850
+
U+200D
851
+
852
+
Overview:
853
+
This may occur in Indic scripts in a consonant-conjunct context
854
+
(immediately following a virama), to control required display of
855
+
such conjuncts.
856
+
857
+
Lookup:
858
+
True
859
+
860
+
Rule Set:
861
+
862
+
False;
863
+
864
+
If Canonical_Combining_Class(Before(cp)) .eq. Virama Then True;
865
+
866
+
Appendix A.3. MIDDLE DOT
867
+
868
+
Code point:
869
+
U+00B7
870
+
871
+
Overview:
872
+
Between 'l' (U+006C) characters only, used to permit the Catalan
873
+
character ela geminada to be expressed.
874
+
875
+
Lookup:
876
+
False
877
+
878
+
Rule Set:
879
+
880
+
False;
881
+
882
+
If Before(cp) .eq. U+006C And
883
+
884
+
After(cp) .eq. U+006C Then True;
885
+
886
+
887
+
888
+
889
+
890
+
891
+
892
+
893
+
894
+
895
+
896
+
897
+
898
+
Faltstrom Standards Track [Page 16]
899
+
900
+
RFC 5892 IDNA Code Points August 2010
901
+
902
+
903
+
Appendix A.4. GREEK LOWER NUMERAL SIGN (KERAIA)
904
+
905
+
Code point:
906
+
U+0375
907
+
908
+
Overview:
909
+
The script of the following character MUST be Greek.
910
+
911
+
Lookup:
912
+
False
913
+
914
+
Rule Set:
915
+
916
+
False;
917
+
918
+
If Script(After(cp)) .eq. Greek Then True;
919
+
920
+
Appendix A.5. HEBREW PUNCTUATION GERESH
921
+
922
+
Code point:
923
+
U+05F3
924
+
925
+
Overview:
926
+
The script of the preceding character MUST be Hebrew.
927
+
928
+
Lookup:
929
+
False
930
+
931
+
Rule Set:
932
+
933
+
False;
934
+
935
+
If Script(Before(cp)) .eq. Hebrew Then True;
936
+
937
+
938
+
939
+
940
+
941
+
942
+
943
+
944
+
945
+
946
+
947
+
948
+
949
+
950
+
951
+
952
+
953
+
954
+
Faltstrom Standards Track [Page 17]
955
+
956
+
RFC 5892 IDNA Code Points August 2010
957
+
958
+
959
+
Appendix A.6. HEBREW PUNCTUATION GERSHAYIM
960
+
961
+
Code point:
962
+
U+05F4
963
+
964
+
Overview:
965
+
The script of the preceding character MUST be Hebrew.
966
+
967
+
Lookup:
968
+
False
969
+
970
+
Rule Set:
971
+
972
+
False;
973
+
974
+
If Script(Before(cp)) .eq. Hebrew Then True;
975
+
976
+
Appendix A.7. KATAKANA MIDDLE DOT
977
+
978
+
Code point:
979
+
U+30FB
980
+
981
+
Overview:
982
+
Note that the Script of Katakana Middle Dot is not any of
983
+
"Hiragana", "Katakana", or "Han". The effect of this rule is to
984
+
require at least one character in the label to be in one of those
985
+
scripts.
986
+
987
+
Lookup:
988
+
False
989
+
990
+
Rule Set:
991
+
992
+
False;
993
+
994
+
For All Characters:
995
+
996
+
If Script(cp) .in. {Hiragana, Katakana, Han} Then True;
997
+
998
+
End For;
999
+
1000
+
1001
+
1002
+
1003
+
1004
+
1005
+
1006
+
1007
+
1008
+
1009
+
1010
+
Faltstrom Standards Track [Page 18]
1011
+
1012
+
RFC 5892 IDNA Code Points August 2010
1013
+
1014
+
1015
+
Appendix A.8. ARABIC-INDIC DIGITS
1016
+
1017
+
Code point:
1018
+
0660..0669
1019
+
1020
+
Overview:
1021
+
Can not be mixed with Extended Arabic-Indic Digits.
1022
+
1023
+
Lookup:
1024
+
False
1025
+
1026
+
Rule Set:
1027
+
1028
+
True;
1029
+
1030
+
For All Characters:
1031
+
1032
+
If cp .in. 06F0..06F9 Then False;
1033
+
1034
+
End For;
1035
+
1036
+
Appendix A.9. EXTENDED ARABIC-INDIC DIGITS
1037
+
1038
+
Code point:
1039
+
06F0..06F9
1040
+
1041
+
Overview:
1042
+
Can not be mixed with Arabic-Indic Digits.
1043
+
1044
+
Lookup:
1045
+
False
1046
+
1047
+
Rule Set:
1048
+
1049
+
True;
1050
+
1051
+
For All Characters:
1052
+
1053
+
If cp .in. 0660..0669 Then False;
1054
+
1055
+
End For;
1056
+
1057
+
1058
+
1059
+
1060
+
1061
+
1062
+
1063
+
1064
+
1065
+
1066
+
Faltstrom Standards Track [Page 19]
1067
+
1068
+
RFC 5892 IDNA Code Points August 2010
1069
+
1070
+
1071
+
Appendix B. Code Points 0x0000 - 0x10FFFF
1072
+
1073
+
If one applies the rules (Section 3) to the code points 0x0000 to
1074
+
0x10FFFF to Unicode 5.2, the result is as follows.
1075
+
1076
+
This list is non-normative, and only included for illustrative
1077
+
purposes. Specifically, what is displayed in the third column is not
1078
+
the formal name of the code point (as defined in Section 4.8 of The
1079
+
Unicode Standard [Unicode52]). The differences exist, for example,
1080
+
for the code points that have the code point value as part of the
1081
+
name (for example, CJK UNIFIED IDEOGRAPH-4E00) and the naming of
1082
+
Hangul syllables. For many code points, what you see is the official
1083
+
name.
1084
+
1085
+
Appendix B.1. Code Points in Unicode Character Database (UCD) Format
1086
+
1087
+
0000..002C ; DISALLOWED # <control>..COMMA
1088
+
002D ; PVALID # HYPHEN-MINUS
1089
+
002E..002F ; DISALLOWED # FULL STOP..SOLIDUS
1090
+
0030..0039 ; PVALID # DIGIT ZERO..DIGIT NINE
1091
+
003A..0060 ; DISALLOWED # COLON..GRAVE ACCENT
1092
+
0061..007A ; PVALID # LATIN SMALL LETTER A..LATIN SMALL LETTER Z
1093
+
007B..00B6 ; DISALLOWED # LEFT CURLY BRACKET..PILCROW SIGN
1094
+
00B7 ; CONTEXTO # MIDDLE DOT
1095
+
00B8..00DE ; DISALLOWED # CEDILLA..LATIN CAPITAL LETTER THORN
1096
+
00DF..00F6 ; PVALID # LATIN SMALL LETTER SHARP S..LATIN SMALL LETT
1097
+
00F7 ; DISALLOWED # DIVISION SIGN
1098
+
00F8..00FF ; PVALID # LATIN SMALL LETTER O WITH STROKE..LATIN SMAL
1099
+
0100 ; DISALLOWED # LATIN CAPITAL LETTER A WITH MACRON
1100
+
0101 ; PVALID # LATIN SMALL LETTER A WITH MACRON
1101
+
0102 ; DISALLOWED # LATIN CAPITAL LETTER A WITH BREVE
1102
+
0103 ; PVALID # LATIN SMALL LETTER A WITH BREVE
1103
+
0104 ; DISALLOWED # LATIN CAPITAL LETTER A WITH OGONEK
1104
+
0105 ; PVALID # LATIN SMALL LETTER A WITH OGONEK
1105
+
0106 ; DISALLOWED # LATIN CAPITAL LETTER C WITH ACUTE
1106
+
0107 ; PVALID # LATIN SMALL LETTER C WITH ACUTE
1107
+
0108 ; DISALLOWED # LATIN CAPITAL LETTER C WITH CIRCUMFLEX
1108
+
0109 ; PVALID # LATIN SMALL LETTER C WITH CIRCUMFLEX
1109
+
010A ; DISALLOWED # LATIN CAPITAL LETTER C WITH DOT ABOVE
1110
+
010B ; PVALID # LATIN SMALL LETTER C WITH DOT ABOVE
1111
+
010C ; DISALLOWED # LATIN CAPITAL LETTER C WITH CARON
1112
+
010D ; PVALID # LATIN SMALL LETTER C WITH CARON
1113
+
010E ; DISALLOWED # LATIN CAPITAL LETTER D WITH CARON
1114
+
010F ; PVALID # LATIN SMALL LETTER D WITH CARON
1115
+
0110 ; DISALLOWED # LATIN CAPITAL LETTER D WITH STROKE
1116
+
0111 ; PVALID # LATIN SMALL LETTER D WITH STROKE
1117
+
0112 ; DISALLOWED # LATIN CAPITAL LETTER E WITH MACRON
1118
+
0113 ; PVALID # LATIN SMALL LETTER E WITH MACRON
1119
+
1120
+
1121
+
1122
+
Faltstrom Standards Track [Page 20]
1123
+
1124
+
RFC 5892 IDNA Code Points August 2010
1125
+
1126
+
1127
+
0114 ; DISALLOWED # LATIN CAPITAL LETTER E WITH BREVE
1128
+
0115 ; PVALID # LATIN SMALL LETTER E WITH BREVE
1129
+
0116 ; DISALLOWED # LATIN CAPITAL LETTER E WITH DOT ABOVE
1130
+
0117 ; PVALID # LATIN SMALL LETTER E WITH DOT ABOVE
1131
+
0118 ; DISALLOWED # LATIN CAPITAL LETTER E WITH OGONEK
1132
+
0119 ; PVALID # LATIN SMALL LETTER E WITH OGONEK
1133
+
011A ; DISALLOWED # LATIN CAPITAL LETTER E WITH CARON
1134
+
011B ; PVALID # LATIN SMALL LETTER E WITH CARON
1135
+
011C ; DISALLOWED # LATIN CAPITAL LETTER G WITH CIRCUMFLEX
1136
+
011D ; PVALID # LATIN SMALL LETTER G WITH CIRCUMFLEX
1137
+
011E ; DISALLOWED # LATIN CAPITAL LETTER G WITH BREVE
1138
+
011F ; PVALID # LATIN SMALL LETTER G WITH BREVE
1139
+
0120 ; DISALLOWED # LATIN CAPITAL LETTER G WITH DOT ABOVE
1140
+
0121 ; PVALID # LATIN SMALL LETTER G WITH DOT ABOVE
1141
+
0122 ; DISALLOWED # LATIN CAPITAL LETTER G WITH CEDILLA
1142
+
0123 ; PVALID # LATIN SMALL LETTER G WITH CEDILLA
1143
+
0124 ; DISALLOWED # LATIN CAPITAL LETTER H WITH CIRCUMFLEX
1144
+
0125 ; PVALID # LATIN SMALL LETTER H WITH CIRCUMFLEX
1145
+
0126 ; DISALLOWED # LATIN CAPITAL LETTER H WITH STROKE
1146
+
0127 ; PVALID # LATIN SMALL LETTER H WITH STROKE
1147
+
0128 ; DISALLOWED # LATIN CAPITAL LETTER I WITH TILDE
1148
+
0129 ; PVALID # LATIN SMALL LETTER I WITH TILDE
1149
+
012A ; DISALLOWED # LATIN CAPITAL LETTER I WITH MACRON
1150
+
012B ; PVALID # LATIN SMALL LETTER I WITH MACRON
1151
+
012C ; DISALLOWED # LATIN CAPITAL LETTER I WITH BREVE
1152
+
012D ; PVALID # LATIN SMALL LETTER I WITH BREVE
1153
+
012E ; DISALLOWED # LATIN CAPITAL LETTER I WITH OGONEK
1154
+
012F ; PVALID # LATIN SMALL LETTER I WITH OGONEK
1155
+
0130 ; DISALLOWED # LATIN CAPITAL LETTER I WITH DOT ABOVE
1156
+
0131 ; PVALID # LATIN SMALL LETTER DOTLESS I
1157
+
0132..0134 ; DISALLOWED # LATIN CAPITAL LIGATURE IJ..LATIN CAPITAL LET
1158
+
0135 ; PVALID # LATIN SMALL LETTER J WITH CIRCUMFLEX
1159
+
0136 ; DISALLOWED # LATIN CAPITAL LETTER K WITH CEDILLA
1160
+
0137..0138 ; PVALID # LATIN SMALL LETTER K WITH CEDILLA..LATIN SMA
1161
+
0139 ; DISALLOWED # LATIN CAPITAL LETTER L WITH ACUTE
1162
+
013A ; PVALID # LATIN SMALL LETTER L WITH ACUTE
1163
+
013B ; DISALLOWED # LATIN CAPITAL LETTER L WITH CEDILLA
1164
+
013C ; PVALID # LATIN SMALL LETTER L WITH CEDILLA
1165
+
013D ; DISALLOWED # LATIN CAPITAL LETTER L WITH CARON
1166
+
013E ; PVALID # LATIN SMALL LETTER L WITH CARON
1167
+
013F..0141 ; DISALLOWED # LATIN CAPITAL LETTER L WITH MIDDLE DOT..LATI
1168
+
0142 ; PVALID # LATIN SMALL LETTER L WITH STROKE
1169
+
0143 ; DISALLOWED # LATIN CAPITAL LETTER N WITH ACUTE
1170
+
0144 ; PVALID # LATIN SMALL LETTER N WITH ACUTE
1171
+
0145 ; DISALLOWED # LATIN CAPITAL LETTER N WITH CEDILLA
1172
+
0146 ; PVALID # LATIN SMALL LETTER N WITH CEDILLA
1173
+
0147 ; DISALLOWED # LATIN CAPITAL LETTER N WITH CARON
1174
+
0148 ; PVALID # LATIN SMALL LETTER N WITH CARON
1175
+
1176
+
1177
+
1178
+
Faltstrom Standards Track [Page 21]
1179
+
1180
+
RFC 5892 IDNA Code Points August 2010
1181
+
1182
+
1183
+
0149..014A ; DISALLOWED # LATIN SMALL LETTER N PRECEDED BY APOSTROPHE.
1184
+
014B ; PVALID # LATIN SMALL LETTER ENG
1185
+
014C ; DISALLOWED # LATIN CAPITAL LETTER O WITH MACRON
1186
+
014D ; PVALID # LATIN SMALL LETTER O WITH MACRON
1187
+
014E ; DISALLOWED # LATIN CAPITAL LETTER O WITH BREVE
1188
+
014F ; PVALID # LATIN SMALL LETTER O WITH BREVE
1189
+
0150 ; DISALLOWED # LATIN CAPITAL LETTER O WITH DOUBLE ACUTE
1190
+
0151 ; PVALID # LATIN SMALL LETTER O WITH DOUBLE ACUTE
1191
+
0152 ; DISALLOWED # LATIN CAPITAL LIGATURE OE
1192
+
0153 ; PVALID # LATIN SMALL LIGATURE OE
1193
+
0154 ; DISALLOWED # LATIN CAPITAL LETTER R WITH ACUTE
1194
+
0155 ; PVALID # LATIN SMALL LETTER R WITH ACUTE
1195
+
0156 ; DISALLOWED # LATIN CAPITAL LETTER R WITH CEDILLA
1196
+
0157 ; PVALID # LATIN SMALL LETTER R WITH CEDILLA
1197
+
0158 ; DISALLOWED # LATIN CAPITAL LETTER R WITH CARON
1198
+
0159 ; PVALID # LATIN SMALL LETTER R WITH CARON
1199
+
015A ; DISALLOWED # LATIN CAPITAL LETTER S WITH ACUTE
1200
+
015B ; PVALID # LATIN SMALL LETTER S WITH ACUTE
1201
+
015C ; DISALLOWED # LATIN CAPITAL LETTER S WITH CIRCUMFLEX
1202
+
015D ; PVALID # LATIN SMALL LETTER S WITH CIRCUMFLEX
1203
+
015E ; DISALLOWED # LATIN CAPITAL LETTER S WITH CEDILLA
1204
+
015F ; PVALID # LATIN SMALL LETTER S WITH CEDILLA
1205
+
0160 ; DISALLOWED # LATIN CAPITAL LETTER S WITH CARON
1206
+
0161 ; PVALID # LATIN SMALL LETTER S WITH CARON
1207
+
0162 ; DISALLOWED # LATIN CAPITAL LETTER T WITH CEDILLA
1208
+
0163 ; PVALID # LATIN SMALL LETTER T WITH CEDILLA
1209
+
0164 ; DISALLOWED # LATIN CAPITAL LETTER T WITH CARON
1210
+
0165 ; PVALID # LATIN SMALL LETTER T WITH CARON
1211
+
0166 ; DISALLOWED # LATIN CAPITAL LETTER T WITH STROKE
1212
+
0167 ; PVALID # LATIN SMALL LETTER T WITH STROKE
1213
+
0168 ; DISALLOWED # LATIN CAPITAL LETTER U WITH TILDE
1214
+
0169 ; PVALID # LATIN SMALL LETTER U WITH TILDE
1215
+
016A ; DISALLOWED # LATIN CAPITAL LETTER U WITH MACRON
1216
+
016B ; PVALID # LATIN SMALL LETTER U WITH MACRON
1217
+
016C ; DISALLOWED # LATIN CAPITAL LETTER U WITH BREVE
1218
+
016D ; PVALID # LATIN SMALL LETTER U WITH BREVE
1219
+
016E ; DISALLOWED # LATIN CAPITAL LETTER U WITH RING ABOVE
1220
+
016F ; PVALID # LATIN SMALL LETTER U WITH RING ABOVE
1221
+
0170 ; DISALLOWED # LATIN CAPITAL LETTER U WITH DOUBLE ACUTE
1222
+
0171 ; PVALID # LATIN SMALL LETTER U WITH DOUBLE ACUTE
1223
+
0172 ; DISALLOWED # LATIN CAPITAL LETTER U WITH OGONEK
1224
+
0173 ; PVALID # LATIN SMALL LETTER U WITH OGONEK
1225
+
0174 ; DISALLOWED # LATIN CAPITAL LETTER W WITH CIRCUMFLEX
1226
+
0175 ; PVALID # LATIN SMALL LETTER W WITH CIRCUMFLEX
1227
+
0176 ; DISALLOWED # LATIN CAPITAL LETTER Y WITH CIRCUMFLEX
1228
+
0177 ; PVALID # LATIN SMALL LETTER Y WITH CIRCUMFLEX
1229
+
0178..0179 ; DISALLOWED # LATIN CAPITAL LETTER Y WITH DIAERESIS..LATIN
1230
+
017A ; PVALID # LATIN SMALL LETTER Z WITH ACUTE
1231
+
1232
+
1233
+
1234
+
Faltstrom Standards Track [Page 22]
1235
+
1236
+
RFC 5892 IDNA Code Points August 2010
1237
+
1238
+
1239
+
017B ; DISALLOWED # LATIN CAPITAL LETTER Z WITH DOT ABOVE
1240
+
017C ; PVALID # LATIN SMALL LETTER Z WITH DOT ABOVE
1241
+
017D ; DISALLOWED # LATIN CAPITAL LETTER Z WITH CARON
1242
+
017E ; PVALID # LATIN SMALL LETTER Z WITH CARON
1243
+
017F ; DISALLOWED # LATIN SMALL LETTER LONG S
1244
+
0180 ; PVALID # LATIN SMALL LETTER B WITH STROKE
1245
+
0181..0182 ; DISALLOWED # LATIN CAPITAL LETTER B WITH HOOK..LATIN CAPI
1246
+
0183 ; PVALID # LATIN SMALL LETTER B WITH TOPBAR
1247
+
0184 ; DISALLOWED # LATIN CAPITAL LETTER TONE SIX
1248
+
0185 ; PVALID # LATIN SMALL LETTER TONE SIX
1249
+
0186..0187 ; DISALLOWED # LATIN CAPITAL LETTER OPEN O..LATIN CAPITAL L
1250
+
0188 ; PVALID # LATIN SMALL LETTER C WITH HOOK
1251
+
0189..018B ; DISALLOWED # LATIN CAPITAL LETTER AFRICAN D..LATIN CAPITA
1252
+
018C..018D ; PVALID # LATIN SMALL LETTER D WITH TOPBAR..LATIN SMAL
1253
+
018E..0191 ; DISALLOWED # LATIN CAPITAL LETTER REVERSED E..LATIN CAPIT
1254
+
0192 ; PVALID # LATIN SMALL LETTER F WITH HOOK
1255
+
0193..0194 ; DISALLOWED # LATIN CAPITAL LETTER G WITH HOOK..LATIN CAPI
1256
+
0195 ; PVALID # LATIN SMALL LETTER HV
1257
+
0196..0198 ; DISALLOWED # LATIN CAPITAL LETTER IOTA..LATIN CAPITAL LET
1258
+
0199..019B ; PVALID # LATIN SMALL LETTER K WITH HOOK..LATIN SMALL
1259
+
019C..019D ; DISALLOWED # LATIN CAPITAL LETTER TURNED M..LATIN CAPITAL
1260
+
019E ; PVALID # LATIN SMALL LETTER N WITH LONG RIGHT LEG
1261
+
019F..01A0 ; DISALLOWED # LATIN CAPITAL LETTER O WITH MIDDLE TILDE..LA
1262
+
01A1 ; PVALID # LATIN SMALL LETTER O WITH HORN
1263
+
01A2 ; DISALLOWED # LATIN CAPITAL LETTER OI
1264
+
01A3 ; PVALID # LATIN SMALL LETTER OI
1265
+
01A4 ; DISALLOWED # LATIN CAPITAL LETTER P WITH HOOK
1266
+
01A5 ; PVALID # LATIN SMALL LETTER P WITH HOOK
1267
+
01A6..01A7 ; DISALLOWED # LATIN LETTER YR..LATIN CAPITAL LETTER TONE T
1268
+
01A8 ; PVALID # LATIN SMALL LETTER TONE TWO
1269
+
01A9 ; DISALLOWED # LATIN CAPITAL LETTER ESH
1270
+
01AA..01AB ; PVALID # LATIN LETTER REVERSED ESH LOOP..LATIN SMALL
1271
+
01AC ; DISALLOWED # LATIN CAPITAL LETTER T WITH HOOK
1272
+
01AD ; PVALID # LATIN SMALL LETTER T WITH HOOK
1273
+
01AE..01AF ; DISALLOWED # LATIN CAPITAL LETTER T WITH RETROFLEX HOOK..
1274
+
01B0 ; PVALID # LATIN SMALL LETTER U WITH HORN
1275
+
01B1..01B3 ; DISALLOWED # LATIN CAPITAL LETTER UPSILON..LATIN CAPITAL
1276
+
01B4 ; PVALID # LATIN SMALL LETTER Y WITH HOOK
1277
+
01B5 ; DISALLOWED # LATIN CAPITAL LETTER Z WITH STROKE
1278
+
01B6 ; PVALID # LATIN SMALL LETTER Z WITH STROKE
1279
+
01B7..01B8 ; DISALLOWED # LATIN CAPITAL LETTER EZH..LATIN CAPITAL LETT
1280
+
01B9..01BB ; PVALID # LATIN SMALL LETTER EZH REVERSED..LATIN LETTE
1281
+
01BC ; DISALLOWED # LATIN CAPITAL LETTER TONE FIVE
1282
+
01BD..01C3 ; PVALID # LATIN SMALL LETTER TONE FIVE..LATIN LETTER R
1283
+
01C4..01CD ; DISALLOWED # LATIN CAPITAL LETTER DZ WITH CARON..LATIN CA
1284
+
01CE ; PVALID # LATIN SMALL LETTER A WITH CARON
1285
+
01CF ; DISALLOWED # LATIN CAPITAL LETTER I WITH CARON
1286
+
01D0 ; PVALID # LATIN SMALL LETTER I WITH CARON
1287
+
1288
+
1289
+
1290
+
Faltstrom Standards Track [Page 23]
1291
+
1292
+
RFC 5892 IDNA Code Points August 2010
1293
+
1294
+
1295
+
01D1 ; DISALLOWED # LATIN CAPITAL LETTER O WITH CARON
1296
+
01D2 ; PVALID # LATIN SMALL LETTER O WITH CARON
1297
+
01D3 ; DISALLOWED # LATIN CAPITAL LETTER U WITH CARON
1298
+
01D4 ; PVALID # LATIN SMALL LETTER U WITH CARON
1299
+
01D5 ; DISALLOWED # LATIN CAPITAL LETTER U WITH DIAERESIS AND MA
1300
+
01D6 ; PVALID # LATIN SMALL LETTER U WITH DIAERESIS AND MACR
1301
+
01D7 ; DISALLOWED # LATIN CAPITAL LETTER U WITH DIAERESIS AND AC
1302
+
01D8 ; PVALID # LATIN SMALL LETTER U WITH DIAERESIS AND ACUT
1303
+
01D9 ; DISALLOWED # LATIN CAPITAL LETTER U WITH DIAERESIS AND CA
1304
+
01DA ; PVALID # LATIN SMALL LETTER U WITH DIAERESIS AND CARO
1305
+
01DB ; DISALLOWED # LATIN CAPITAL LETTER U WITH DIAERESIS AND GR
1306
+
01DC..01DD ; PVALID # LATIN SMALL LETTER U WITH DIAERESIS AND GRAV
1307
+
01DE ; DISALLOWED # LATIN CAPITAL LETTER A WITH DIAERESIS AND MA
1308
+
01DF ; PVALID # LATIN SMALL LETTER A WITH DIAERESIS AND MACR
1309
+
01E0 ; DISALLOWED # LATIN CAPITAL LETTER A WITH DOT ABOVE AND MA
1310
+
01E1 ; PVALID # LATIN SMALL LETTER A WITH DOT ABOVE AND MACR
1311
+
01E2 ; DISALLOWED # LATIN CAPITAL LETTER AE WITH MACRON
1312
+
01E3 ; PVALID # LATIN SMALL LETTER AE WITH MACRON
1313
+
01E4 ; DISALLOWED # LATIN CAPITAL LETTER G WITH STROKE
1314
+
01E5 ; PVALID # LATIN SMALL LETTER G WITH STROKE
1315
+
01E6 ; DISALLOWED # LATIN CAPITAL LETTER G WITH CARON
1316
+
01E7 ; PVALID # LATIN SMALL LETTER G WITH CARON
1317
+
01E8 ; DISALLOWED # LATIN CAPITAL LETTER K WITH CARON
1318
+
01E9 ; PVALID # LATIN SMALL LETTER K WITH CARON
1319
+
01EA ; DISALLOWED # LATIN CAPITAL LETTER O WITH OGONEK
1320
+
01EB ; PVALID # LATIN SMALL LETTER O WITH OGONEK
1321
+
01EC ; DISALLOWED # LATIN CAPITAL LETTER O WITH OGONEK AND MACRO
1322
+
01ED ; PVALID # LATIN SMALL LETTER O WITH OGONEK AND MACRON
1323
+
01EE ; DISALLOWED # LATIN CAPITAL LETTER EZH WITH CARON
1324
+
01EF..01F0 ; PVALID # LATIN SMALL LETTER EZH WITH CARON..LATIN SMA
1325
+
01F1..01F4 ; DISALLOWED # LATIN CAPITAL LETTER DZ..LATIN CAPITAL LETTE
1326
+
01F5 ; PVALID # LATIN SMALL LETTER G WITH ACUTE
1327
+
01F6..01F8 ; DISALLOWED # LATIN CAPITAL LETTER HWAIR..LATIN CAPITAL LE
1328
+
01F9 ; PVALID # LATIN SMALL LETTER N WITH GRAVE
1329
+
01FA ; DISALLOWED # LATIN CAPITAL LETTER A WITH RING ABOVE AND A
1330
+
01FB ; PVALID # LATIN SMALL LETTER A WITH RING ABOVE AND ACU
1331
+
01FC ; DISALLOWED # LATIN CAPITAL LETTER AE WITH ACUTE
1332
+
01FD ; PVALID # LATIN SMALL LETTER AE WITH ACUTE
1333
+
01FE ; DISALLOWED # LATIN CAPITAL LETTER O WITH STROKE AND ACUTE
1334
+
01FF ; PVALID # LATIN SMALL LETTER O WITH STROKE AND ACUTE
1335
+
0200 ; DISALLOWED # LATIN CAPITAL LETTER A WITH DOUBLE GRAVE
1336
+
0201 ; PVALID # LATIN SMALL LETTER A WITH DOUBLE GRAVE
1337
+
0202 ; DISALLOWED # LATIN CAPITAL LETTER A WITH INVERTED BREVE
1338
+
0203 ; PVALID # LATIN SMALL LETTER A WITH INVERTED BREVE
1339
+
0204 ; DISALLOWED # LATIN CAPITAL LETTER E WITH DOUBLE GRAVE
1340
+
0205 ; PVALID # LATIN SMALL LETTER E WITH DOUBLE GRAVE
1341
+
0206 ; DISALLOWED # LATIN CAPITAL LETTER E WITH INVERTED BREVE
1342
+
0207 ; PVALID # LATIN SMALL LETTER E WITH INVERTED BREVE
1343
+
1344
+
1345
+
1346
+
Faltstrom Standards Track [Page 24]
1347
+
1348
+
RFC 5892 IDNA Code Points August 2010
1349
+
1350
+
1351
+
0208 ; DISALLOWED # LATIN CAPITAL LETTER I WITH DOUBLE GRAVE
1352
+
0209 ; PVALID # LATIN SMALL LETTER I WITH DOUBLE GRAVE
1353
+
020A ; DISALLOWED # LATIN CAPITAL LETTER I WITH INVERTED BREVE
1354
+
020B ; PVALID # LATIN SMALL LETTER I WITH INVERTED BREVE
1355
+
020C ; DISALLOWED # LATIN CAPITAL LETTER O WITH DOUBLE GRAVE
1356
+
020D ; PVALID # LATIN SMALL LETTER O WITH DOUBLE GRAVE
1357
+
020E ; DISALLOWED # LATIN CAPITAL LETTER O WITH INVERTED BREVE
1358
+
020F ; PVALID # LATIN SMALL LETTER O WITH INVERTED BREVE
1359
+
0210 ; DISALLOWED # LATIN CAPITAL LETTER R WITH DOUBLE GRAVE
1360
+
0211 ; PVALID # LATIN SMALL LETTER R WITH DOUBLE GRAVE
1361
+
0212 ; DISALLOWED # LATIN CAPITAL LETTER R WITH INVERTED BREVE
1362
+
0213 ; PVALID # LATIN SMALL LETTER R WITH INVERTED BREVE
1363
+
0214 ; DISALLOWED # LATIN CAPITAL LETTER U WITH DOUBLE GRAVE
1364
+
0215 ; PVALID # LATIN SMALL LETTER U WITH DOUBLE GRAVE
1365
+
0216 ; DISALLOWED # LATIN CAPITAL LETTER U WITH INVERTED BREVE
1366
+
0217 ; PVALID # LATIN SMALL LETTER U WITH INVERTED BREVE
1367
+
0218 ; DISALLOWED # LATIN CAPITAL LETTER S WITH COMMA BELOW
1368
+
0219 ; PVALID # LATIN SMALL LETTER S WITH COMMA BELOW
1369
+
021A ; DISALLOWED # LATIN CAPITAL LETTER T WITH COMMA BELOW
1370
+
021B ; PVALID # LATIN SMALL LETTER T WITH COMMA BELOW
1371
+
021C ; DISALLOWED # LATIN CAPITAL LETTER YOGH
1372
+
021D ; PVALID # LATIN SMALL LETTER YOGH
1373
+
021E ; DISALLOWED # LATIN CAPITAL LETTER H WITH CARON
1374
+
021F ; PVALID # LATIN SMALL LETTER H WITH CARON
1375
+
0220 ; DISALLOWED # LATIN CAPITAL LETTER N WITH LONG RIGHT LEG
1376
+
0221 ; PVALID # LATIN SMALL LETTER D WITH CURL
1377
+
0222 ; DISALLOWED # LATIN CAPITAL LETTER OU
1378
+
0223 ; PVALID # LATIN SMALL LETTER OU
1379
+
0224 ; DISALLOWED # LATIN CAPITAL LETTER Z WITH HOOK
1380
+
0225 ; PVALID # LATIN SMALL LETTER Z WITH HOOK
1381
+
0226 ; DISALLOWED # LATIN CAPITAL LETTER A WITH DOT ABOVE
1382
+
0227 ; PVALID # LATIN SMALL LETTER A WITH DOT ABOVE
1383
+
0228 ; DISALLOWED # LATIN CAPITAL LETTER E WITH CEDILLA
1384
+
0229 ; PVALID # LATIN SMALL LETTER E WITH CEDILLA
1385
+
022A ; DISALLOWED # LATIN CAPITAL LETTER O WITH DIAERESIS AND MA
1386
+
022B ; PVALID # LATIN SMALL LETTER O WITH DIAERESIS AND MACR
1387
+
022C ; DISALLOWED # LATIN CAPITAL LETTER O WITH TILDE AND MACRON
1388
+
022D ; PVALID # LATIN SMALL LETTER O WITH TILDE AND MACRON
1389
+
022E ; DISALLOWED # LATIN CAPITAL LETTER O WITH DOT ABOVE
1390
+
022F ; PVALID # LATIN SMALL LETTER O WITH DOT ABOVE
1391
+
0230 ; DISALLOWED # LATIN CAPITAL LETTER O WITH DOT ABOVE AND MA
1392
+
0231 ; PVALID # LATIN SMALL LETTER O WITH DOT ABOVE AND MACR
1393
+
0232 ; DISALLOWED # LATIN CAPITAL LETTER Y WITH MACRON
1394
+
0233..0239 ; PVALID # LATIN SMALL LETTER Y WITH MACRON..LATIN SMAL
1395
+
023A..023B ; DISALLOWED # LATIN CAPITAL LETTER A WITH STROKE..LATIN CA
1396
+
023C ; PVALID # LATIN SMALL LETTER C WITH STROKE
1397
+
023D..023E ; DISALLOWED # LATIN CAPITAL LETTER L WITH BAR..LATIN CAPIT
1398
+
023F..0240 ; PVALID # LATIN SMALL LETTER S WITH SWASH TAIL..LATIN
1399
+
1400
+
1401
+
1402
+
Faltstrom Standards Track [Page 25]
1403
+
1404
+
RFC 5892 IDNA Code Points August 2010
1405
+
1406
+
1407
+
0241 ; DISALLOWED # LATIN CAPITAL LETTER GLOTTAL STOP
1408
+
0242 ; PVALID # LATIN SMALL LETTER GLOTTAL STOP
1409
+
0243..0246 ; DISALLOWED # LATIN CAPITAL LETTER B WITH STROKE..LATIN CA
1410
+
0247 ; PVALID # LATIN SMALL LETTER E WITH STROKE
1411
+
0248 ; DISALLOWED # LATIN CAPITAL LETTER J WITH STROKE
1412
+
0249 ; PVALID # LATIN SMALL LETTER J WITH STROKE
1413
+
024A ; DISALLOWED # LATIN CAPITAL LETTER SMALL Q WITH HOOK TAIL
1414
+
024B ; PVALID # LATIN SMALL LETTER Q WITH HOOK TAIL
1415
+
024C ; DISALLOWED # LATIN CAPITAL LETTER R WITH STROKE
1416
+
024D ; PVALID # LATIN SMALL LETTER R WITH STROKE
1417
+
024E ; DISALLOWED # LATIN CAPITAL LETTER Y WITH STROKE
1418
+
024F..02AF ; PVALID # LATIN SMALL LETTER Y WITH STROKE..LATIN SMAL
1419
+
02B0..02B8 ; DISALLOWED # MODIFIER LETTER SMALL H..MODIFIER LETTER SMA
1420
+
02B9..02C1 ; PVALID # MODIFIER LETTER PRIME..MODIFIER LETTER REVER
1421
+
02C2..02C5 ; DISALLOWED # MODIFIER LETTER LEFT ARROWHEAD..MODIFIER LET
1422
+
02C6..02D1 ; PVALID # MODIFIER LETTER CIRCUMFLEX ACCENT..MODIFIER
1423
+
02D2..02EB ; DISALLOWED # MODIFIER LETTER CENTRED RIGHT HALF RING..MOD
1424
+
02EC ; PVALID # MODIFIER LETTER VOICING
1425
+
02ED ; DISALLOWED # MODIFIER LETTER UNASPIRATED
1426
+
02EE ; PVALID # MODIFIER LETTER DOUBLE APOSTROPHE
1427
+
02EF..02FF ; DISALLOWED # MODIFIER LETTER LOW DOWN ARROWHEAD..MODIFIER
1428
+
0300..033F ; PVALID # COMBINING GRAVE ACCENT..COMBINING DOUBLE OVE
1429
+
0340..0341 ; DISALLOWED # COMBINING GRAVE TONE MARK..COMBINING ACUTE T
1430
+
0342 ; PVALID # COMBINING GREEK PERISPOMENI
1431
+
0343..0345 ; DISALLOWED # COMBINING GREEK KORONIS..COMBINING GREEK YPO
1432
+
0346..034E ; PVALID # COMBINING BRIDGE ABOVE..COMBINING UPWARDS AR
1433
+
034F ; DISALLOWED # COMBINING GRAPHEME JOINER
1434
+
0350..036F ; PVALID # COMBINING RIGHT ARROWHEAD ABOVE..COMBINING L
1435
+
0370 ; DISALLOWED # GREEK CAPITAL LETTER HETA
1436
+
0371 ; PVALID # GREEK SMALL LETTER HETA
1437
+
0372 ; DISALLOWED # GREEK CAPITAL LETTER ARCHAIC SAMPI
1438
+
0373 ; PVALID # GREEK SMALL LETTER ARCHAIC SAMPI
1439
+
0374 ; DISALLOWED # GREEK NUMERAL SIGN
1440
+
0375 ; CONTEXTO # GREEK LOWER NUMERAL SIGN
1441
+
0376 ; DISALLOWED # GREEK CAPITAL LETTER PAMPHYLIAN DIGAMMA
1442
+
0377 ; PVALID # GREEK SMALL LETTER PAMPHYLIAN DIGAMMA
1443
+
0378..0379 ; UNASSIGNED # <reserved>..<reserved>
1444
+
037A ; DISALLOWED # GREEK YPOGEGRAMMENI
1445
+
037B..037D ; PVALID # GREEK SMALL REVERSED LUNATE SIGMA SYMBOL..GR
1446
+
037E ; DISALLOWED # GREEK QUESTION MARK
1447
+
037F..0383 ; UNASSIGNED # <reserved>..<reserved>
1448
+
0384..038A ; DISALLOWED # GREEK TONOS..GREEK CAPITAL LETTER IOTA WITH
1449
+
038B ; UNASSIGNED # <reserved>
1450
+
038C ; DISALLOWED # GREEK CAPITAL LETTER OMICRON WITH TONOS
1451
+
038D ; UNASSIGNED # <reserved>
1452
+
038E..038F ; DISALLOWED # GREEK CAPITAL LETTER UPSILON WITH TONOS..GRE
1453
+
0390 ; PVALID # GREEK SMALL LETTER IOTA WITH DIALYTIKA AND T
1454
+
0391..03A1 ; DISALLOWED # GREEK CAPITAL LETTER ALPHA..GREEK CAPITAL LE
1455
+
1456
+
1457
+
1458
+
Faltstrom Standards Track [Page 26]
1459
+
1460
+
RFC 5892 IDNA Code Points August 2010
1461
+
1462
+
1463
+
03A2 ; UNASSIGNED # <reserved>
1464
+
03A3..03AB ; DISALLOWED # GREEK CAPITAL LETTER SIGMA..GREEK CAPITAL LE
1465
+
03AC..03CE ; PVALID # GREEK SMALL LETTER ALPHA WITH TONOS..GREEK S
1466
+
03CF..03D6 ; DISALLOWED # GREEK CAPITAL KAI SYMBOL..GREEK PI SYMBOL
1467
+
03D7 ; PVALID # GREEK KAI SYMBOL
1468
+
03D8 ; DISALLOWED # GREEK LETTER ARCHAIC KOPPA
1469
+
03D9 ; PVALID # GREEK SMALL LETTER ARCHAIC KOPPA
1470
+
03DA ; DISALLOWED # GREEK LETTER STIGMA
1471
+
03DB ; PVALID # GREEK SMALL LETTER STIGMA
1472
+
03DC ; DISALLOWED # GREEK LETTER DIGAMMA
1473
+
03DD ; PVALID # GREEK SMALL LETTER DIGAMMA
1474
+
03DE ; DISALLOWED # GREEK LETTER KOPPA
1475
+
03DF ; PVALID # GREEK SMALL LETTER KOPPA
1476
+
03E0 ; DISALLOWED # GREEK LETTER SAMPI
1477
+
03E1 ; PVALID # GREEK SMALL LETTER SAMPI
1478
+
03E2 ; DISALLOWED # COPTIC CAPITAL LETTER SHEI
1479
+
03E3 ; PVALID # COPTIC SMALL LETTER SHEI
1480
+
03E4 ; DISALLOWED # COPTIC CAPITAL LETTER FEI
1481
+
03E5 ; PVALID # COPTIC SMALL LETTER FEI
1482
+
03E6 ; DISALLOWED # COPTIC CAPITAL LETTER KHEI
1483
+
03E7 ; PVALID # COPTIC SMALL LETTER KHEI
1484
+
03E8 ; DISALLOWED # COPTIC CAPITAL LETTER HORI
1485
+
03E9 ; PVALID # COPTIC SMALL LETTER HORI
1486
+
03EA ; DISALLOWED # COPTIC CAPITAL LETTER GANGIA
1487
+
03EB ; PVALID # COPTIC SMALL LETTER GANGIA
1488
+
03EC ; DISALLOWED # COPTIC CAPITAL LETTER SHIMA
1489
+
03ED ; PVALID # COPTIC SMALL LETTER SHIMA
1490
+
03EE ; DISALLOWED # COPTIC CAPITAL LETTER DEI
1491
+
03EF ; PVALID # COPTIC SMALL LETTER DEI
1492
+
03F0..03F2 ; DISALLOWED # GREEK KAPPA SYMBOL..GREEK LUNATE SIGMA SYMBO
1493
+
03F3 ; PVALID # GREEK LETTER YOT
1494
+
03F4..03F7 ; DISALLOWED # GREEK CAPITAL THETA SYMBOL..GREEK CAPITAL LE
1495
+
03F8 ; PVALID # GREEK SMALL LETTER SHO
1496
+
03F9..03FA ; DISALLOWED # GREEK CAPITAL LUNATE SIGMA SYMBOL..GREEK CAP
1497
+
03FB..03FC ; PVALID # GREEK SMALL LETTER SAN..GREEK RHO WITH STROK
1498
+
03FD..042F ; DISALLOWED # GREEK CAPITAL REVERSED LUNATE SIGMA SYMBOL..
1499
+
0430..045F ; PVALID # CYRILLIC SMALL LETTER A..CYRILLIC SMALL LETT
1500
+
0460 ; DISALLOWED # CYRILLIC CAPITAL LETTER OMEGA
1501
+
0461 ; PVALID # CYRILLIC SMALL LETTER OMEGA
1502
+
0462 ; DISALLOWED # CYRILLIC CAPITAL LETTER YAT
1503
+
0463 ; PVALID # CYRILLIC SMALL LETTER YAT
1504
+
0464 ; DISALLOWED # CYRILLIC CAPITAL LETTER IOTIFIED E
1505
+
0465 ; PVALID # CYRILLIC SMALL LETTER IOTIFIED E
1506
+
0466 ; DISALLOWED # CYRILLIC CAPITAL LETTER LITTLE YUS
1507
+
0467 ; PVALID # CYRILLIC SMALL LETTER LITTLE YUS
1508
+
0468 ; DISALLOWED # CYRILLIC CAPITAL LETTER IOTIFIED LITTLE YUS
1509
+
0469 ; PVALID # CYRILLIC SMALL LETTER IOTIFIED LITTLE YUS
1510
+
046A ; DISALLOWED # CYRILLIC CAPITAL LETTER BIG YUS
1511
+
1512
+
1513
+
1514
+
Faltstrom Standards Track [Page 27]
1515
+
1516
+
RFC 5892 IDNA Code Points August 2010
1517
+
1518
+
1519
+
046B ; PVALID # CYRILLIC SMALL LETTER BIG YUS
1520
+
046C ; DISALLOWED # CYRILLIC CAPITAL LETTER IOTIFIED BIG YUS
1521
+
046D ; PVALID # CYRILLIC SMALL LETTER IOTIFIED BIG YUS
1522
+
046E ; DISALLOWED # CYRILLIC CAPITAL LETTER KSI
1523
+
046F ; PVALID # CYRILLIC SMALL LETTER KSI
1524
+
0470 ; DISALLOWED # CYRILLIC CAPITAL LETTER PSI
1525
+
0471 ; PVALID # CYRILLIC SMALL LETTER PSI
1526
+
0472 ; DISALLOWED # CYRILLIC CAPITAL LETTER FITA
1527
+
0473 ; PVALID # CYRILLIC SMALL LETTER FITA
1528
+
0474 ; DISALLOWED # CYRILLIC CAPITAL LETTER IZHITSA
1529
+
0475 ; PVALID # CYRILLIC SMALL LETTER IZHITSA
1530
+
0476 ; DISALLOWED # CYRILLIC CAPITAL LETTER IZHITSA WITH DOUBLE
1531
+
0477 ; PVALID # CYRILLIC SMALL LETTER IZHITSA WITH DOUBLE GR
1532
+
0478 ; DISALLOWED # CYRILLIC CAPITAL LETTER UK
1533
+
0479 ; PVALID # CYRILLIC SMALL LETTER UK
1534
+
047A ; DISALLOWED # CYRILLIC CAPITAL LETTER ROUND OMEGA
1535
+
047B ; PVALID # CYRILLIC SMALL LETTER ROUND OMEGA
1536
+
047C ; DISALLOWED # CYRILLIC CAPITAL LETTER OMEGA WITH TITLO
1537
+
047D ; PVALID # CYRILLIC SMALL LETTER OMEGA WITH TITLO
1538
+
047E ; DISALLOWED # CYRILLIC CAPITAL LETTER OT
1539
+
047F ; PVALID # CYRILLIC SMALL LETTER OT
1540
+
0480 ; DISALLOWED # CYRILLIC CAPITAL LETTER KOPPA
1541
+
0481 ; PVALID # CYRILLIC SMALL LETTER KOPPA
1542
+
0482 ; DISALLOWED # CYRILLIC THOUSANDS SIGN
1543
+
0483..0487 ; PVALID # COMBINING CYRILLIC TITLO..COMBINING CYRILLIC
1544
+
0488..048A ; DISALLOWED # COMBINING CYRILLIC HUNDRED THOUSANDS SIGN..C
1545
+
048B ; PVALID # CYRILLIC SMALL LETTER SHORT I WITH TAIL
1546
+
048C ; DISALLOWED # CYRILLIC CAPITAL LETTER SEMISOFT SIGN
1547
+
048D ; PVALID # CYRILLIC SMALL LETTER SEMISOFT SIGN
1548
+
048E ; DISALLOWED # CYRILLIC CAPITAL LETTER ER WITH TICK
1549
+
048F ; PVALID # CYRILLIC SMALL LETTER ER WITH TICK
1550
+
0490 ; DISALLOWED # CYRILLIC CAPITAL LETTER GHE WITH UPTURN
1551
+
0491 ; PVALID # CYRILLIC SMALL LETTER GHE WITH UPTURN
1552
+
0492 ; DISALLOWED # CYRILLIC CAPITAL LETTER GHE WITH STROKE
1553
+
0493 ; PVALID # CYRILLIC SMALL LETTER GHE WITH STROKE
1554
+
0494 ; DISALLOWED # CYRILLIC CAPITAL LETTER GHE WITH MIDDLE HOOK
1555
+
0495 ; PVALID # CYRILLIC SMALL LETTER GHE WITH MIDDLE HOOK
1556
+
0496 ; DISALLOWED # CYRILLIC CAPITAL LETTER ZHE WITH DESCENDER
1557
+
0497 ; PVALID # CYRILLIC SMALL LETTER ZHE WITH DESCENDER
1558
+
0498 ; DISALLOWED # CYRILLIC CAPITAL LETTER ZE WITH DESCENDER
1559
+
0499 ; PVALID # CYRILLIC SMALL LETTER ZE WITH DESCENDER
1560
+
049A ; DISALLOWED # CYRILLIC CAPITAL LETTER KA WITH DESCENDER
1561
+
049B ; PVALID # CYRILLIC SMALL LETTER KA WITH DESCENDER
1562
+
049C ; DISALLOWED # CYRILLIC CAPITAL LETTER KA WITH VERTICAL STR
1563
+
049D ; PVALID # CYRILLIC SMALL LETTER KA WITH VERTICAL STROK
1564
+
049E ; DISALLOWED # CYRILLIC CAPITAL LETTER KA WITH STROKE
1565
+
049F ; PVALID # CYRILLIC SMALL LETTER KA WITH STROKE
1566
+
04A0 ; DISALLOWED # CYRILLIC CAPITAL LETTER BASHKIR KA
1567
+
1568
+
1569
+
1570
+
Faltstrom Standards Track [Page 28]
1571
+
1572
+
RFC 5892 IDNA Code Points August 2010
1573
+
1574
+
1575
+
04A1 ; PVALID # CYRILLIC SMALL LETTER BASHKIR KA
1576
+
04A2 ; DISALLOWED # CYRILLIC CAPITAL LETTER EN WITH DESCENDER
1577
+
04A3 ; PVALID # CYRILLIC SMALL LETTER EN WITH DESCENDER
1578
+
04A4 ; DISALLOWED # CYRILLIC CAPITAL LIGATURE EN GHE
1579
+
04A5 ; PVALID # CYRILLIC SMALL LIGATURE EN GHE
1580
+
04A6 ; DISALLOWED # CYRILLIC CAPITAL LETTER PE WITH MIDDLE HOOK
1581
+
04A7 ; PVALID # CYRILLIC SMALL LETTER PE WITH MIDDLE HOOK
1582
+
04A8 ; DISALLOWED # CYRILLIC CAPITAL LETTER ABKHASIAN HA
1583
+
04A9 ; PVALID # CYRILLIC SMALL LETTER ABKHASIAN HA
1584
+
04AA ; DISALLOWED # CYRILLIC CAPITAL LETTER ES WITH DESCENDER
1585
+
04AB ; PVALID # CYRILLIC SMALL LETTER ES WITH DESCENDER
1586
+
04AC ; DISALLOWED # CYRILLIC CAPITAL LETTER TE WITH DESCENDER
1587
+
04AD ; PVALID # CYRILLIC SMALL LETTER TE WITH DESCENDER
1588
+
04AE ; DISALLOWED # CYRILLIC CAPITAL LETTER STRAIGHT U
1589
+
04AF ; PVALID # CYRILLIC SMALL LETTER STRAIGHT U
1590
+
04B0 ; DISALLOWED # CYRILLIC CAPITAL LETTER STRAIGHT U WITH STRO
1591
+
04B1 ; PVALID # CYRILLIC SMALL LETTER STRAIGHT U WITH STROKE
1592
+
04B2 ; DISALLOWED # CYRILLIC CAPITAL LETTER HA WITH DESCENDER
1593
+
04B3 ; PVALID # CYRILLIC SMALL LETTER HA WITH DESCENDER
1594
+
04B4 ; DISALLOWED # CYRILLIC CAPITAL LIGATURE TE TSE
1595
+
04B5 ; PVALID # CYRILLIC SMALL LIGATURE TE TSE
1596
+
04B6 ; DISALLOWED # CYRILLIC CAPITAL LETTER CHE WITH DESCENDER
1597
+
04B7 ; PVALID # CYRILLIC SMALL LETTER CHE WITH DESCENDER
1598
+
04B8 ; DISALLOWED # CYRILLIC CAPITAL LETTER CHE WITH VERTICAL ST
1599
+
04B9 ; PVALID # CYRILLIC SMALL LETTER CHE WITH VERTICAL STRO
1600
+
04BA ; DISALLOWED # CYRILLIC CAPITAL LETTER SHHA
1601
+
04BB ; PVALID # CYRILLIC SMALL LETTER SHHA
1602
+
04BC ; DISALLOWED # CYRILLIC CAPITAL LETTER ABKHASIAN CHE
1603
+
04BD ; PVALID # CYRILLIC SMALL LETTER ABKHASIAN CHE
1604
+
04BE ; DISALLOWED # CYRILLIC CAPITAL LETTER ABKHASIAN CHE WITH D
1605
+
04BF ; PVALID # CYRILLIC SMALL LETTER ABKHASIAN CHE WITH DES
1606
+
04C0..04C1 ; DISALLOWED # CYRILLIC LETTER PALOCHKA..CYRILLIC CAPITAL L
1607
+
04C2 ; PVALID # CYRILLIC SMALL LETTER ZHE WITH BREVE
1608
+
04C3 ; DISALLOWED # CYRILLIC CAPITAL LETTER KA WITH HOOK
1609
+
04C4 ; PVALID # CYRILLIC SMALL LETTER KA WITH HOOK
1610
+
04C5 ; DISALLOWED # CYRILLIC CAPITAL LETTER EL WITH TAIL
1611
+
04C6 ; PVALID # CYRILLIC SMALL LETTER EL WITH TAIL
1612
+
04C7 ; DISALLOWED # CYRILLIC CAPITAL LETTER EN WITH HOOK
1613
+
04C8 ; PVALID # CYRILLIC SMALL LETTER EN WITH HOOK
1614
+
04C9 ; DISALLOWED # CYRILLIC CAPITAL LETTER EN WITH TAIL
1615
+
04CA ; PVALID # CYRILLIC SMALL LETTER EN WITH TAIL
1616
+
04CB ; DISALLOWED # CYRILLIC CAPITAL LETTER KHAKASSIAN CHE
1617
+
04CC ; PVALID # CYRILLIC SMALL LETTER KHAKASSIAN CHE
1618
+
04CD ; DISALLOWED # CYRILLIC CAPITAL LETTER EM WITH TAIL
1619
+
04CE..04CF ; PVALID # CYRILLIC SMALL LETTER EM WITH TAIL..CYRILLIC
1620
+
04D0 ; DISALLOWED # CYRILLIC CAPITAL LETTER A WITH BREVE
1621
+
04D1 ; PVALID # CYRILLIC SMALL LETTER A WITH BREVE
1622
+
04D2 ; DISALLOWED # CYRILLIC CAPITAL LETTER A WITH DIAERESIS
1623
+
1624
+
1625
+
1626
+
Faltstrom Standards Track [Page 29]
1627
+
1628
+
RFC 5892 IDNA Code Points August 2010
1629
+
1630
+
1631
+
04D3 ; PVALID # CYRILLIC SMALL LETTER A WITH DIAERESIS
1632
+
04D4 ; DISALLOWED # CYRILLIC CAPITAL LIGATURE A IE
1633
+
04D5 ; PVALID # CYRILLIC SMALL LIGATURE A IE
1634
+
04D6 ; DISALLOWED # CYRILLIC CAPITAL LETTER IE WITH BREVE
1635
+
04D7 ; PVALID # CYRILLIC SMALL LETTER IE WITH BREVE
1636
+
04D8 ; DISALLOWED # CYRILLIC CAPITAL LETTER SCHWA
1637
+
04D9 ; PVALID # CYRILLIC SMALL LETTER SCHWA
1638
+
04DA ; DISALLOWED # CYRILLIC CAPITAL LETTER SCHWA WITH DIAERESIS
1639
+
04DB ; PVALID # CYRILLIC SMALL LETTER SCHWA WITH DIAERESIS
1640
+
04DC ; DISALLOWED # CYRILLIC CAPITAL LETTER ZHE WITH DIAERESIS
1641
+
04DD ; PVALID # CYRILLIC SMALL LETTER ZHE WITH DIAERESIS
1642
+
04DE ; DISALLOWED # CYRILLIC CAPITAL LETTER ZE WITH DIAERESIS
1643
+
04DF ; PVALID # CYRILLIC SMALL LETTER ZE WITH DIAERESIS
1644
+
04E0 ; DISALLOWED # CYRILLIC CAPITAL LETTER ABKHASIAN DZE
1645
+
04E1 ; PVALID # CYRILLIC SMALL LETTER ABKHASIAN DZE
1646
+
04E2 ; DISALLOWED # CYRILLIC CAPITAL LETTER I WITH MACRON
1647
+
04E3 ; PVALID # CYRILLIC SMALL LETTER I WITH MACRON
1648
+
04E4 ; DISALLOWED # CYRILLIC CAPITAL LETTER I WITH DIAERESIS
1649
+
04E5 ; PVALID # CYRILLIC SMALL LETTER I WITH DIAERESIS
1650
+
04E6 ; DISALLOWED # CYRILLIC CAPITAL LETTER O WITH DIAERESIS
1651
+
04E7 ; PVALID # CYRILLIC SMALL LETTER O WITH DIAERESIS
1652
+
04E8 ; DISALLOWED # CYRILLIC CAPITAL LETTER BARRED O
1653
+
04E9 ; PVALID # CYRILLIC SMALL LETTER BARRED O
1654
+
04EA ; DISALLOWED # CYRILLIC CAPITAL LETTER BARRED O WITH DIAERE
1655
+
04EB ; PVALID # CYRILLIC SMALL LETTER BARRED O WITH DIAERESI
1656
+
04EC ; DISALLOWED # CYRILLIC CAPITAL LETTER E WITH DIAERESIS
1657
+
04ED ; PVALID # CYRILLIC SMALL LETTER E WITH DIAERESIS
1658
+
04EE ; DISALLOWED # CYRILLIC CAPITAL LETTER U WITH MACRON
1659
+
04EF ; PVALID # CYRILLIC SMALL LETTER U WITH MACRON
1660
+
04F0 ; DISALLOWED # CYRILLIC CAPITAL LETTER U WITH DIAERESIS
1661
+
04F1 ; PVALID # CYRILLIC SMALL LETTER U WITH DIAERESIS
1662
+
04F2 ; DISALLOWED # CYRILLIC CAPITAL LETTER U WITH DOUBLE ACUTE
1663
+
04F3 ; PVALID # CYRILLIC SMALL LETTER U WITH DOUBLE ACUTE
1664
+
04F4 ; DISALLOWED # CYRILLIC CAPITAL LETTER CHE WITH DIAERESIS
1665
+
04F5 ; PVALID # CYRILLIC SMALL LETTER CHE WITH DIAERESIS
1666
+
04F6 ; DISALLOWED # CYRILLIC CAPITAL LETTER GHE WITH DESCENDER
1667
+
04F7 ; PVALID # CYRILLIC SMALL LETTER GHE WITH DESCENDER
1668
+
04F8 ; DISALLOWED # CYRILLIC CAPITAL LETTER YERU WITH DIAERESIS
1669
+
04F9 ; PVALID # CYRILLIC SMALL LETTER YERU WITH DIAERESIS
1670
+
04FA ; DISALLOWED # CYRILLIC CAPITAL LETTER GHE WITH STROKE AND
1671
+
04FB ; PVALID # CYRILLIC SMALL LETTER GHE WITH STROKE AND HO
1672
+
04FC ; DISALLOWED # CYRILLIC CAPITAL LETTER HA WITH HOOK
1673
+
04FD ; PVALID # CYRILLIC SMALL LETTER HA WITH HOOK
1674
+
04FE ; DISALLOWED # CYRILLIC CAPITAL LETTER HA WITH STROKE
1675
+
04FF ; PVALID # CYRILLIC SMALL LETTER HA WITH STROKE
1676
+
0500 ; DISALLOWED # CYRILLIC CAPITAL LETTER KOMI DE
1677
+
0501 ; PVALID # CYRILLIC SMALL LETTER KOMI DE
1678
+
0502 ; DISALLOWED # CYRILLIC CAPITAL LETTER KOMI DJE
1679
+
1680
+
1681
+
1682
+
Faltstrom Standards Track [Page 30]
1683
+
1684
+
RFC 5892 IDNA Code Points August 2010
1685
+
1686
+
1687
+
0503 ; PVALID # CYRILLIC SMALL LETTER KOMI DJE
1688
+
0504 ; DISALLOWED # CYRILLIC CAPITAL LETTER KOMI ZJE
1689
+
0505 ; PVALID # CYRILLIC SMALL LETTER KOMI ZJE
1690
+
0506 ; DISALLOWED # CYRILLIC CAPITAL LETTER KOMI DZJE
1691
+
0507 ; PVALID # CYRILLIC SMALL LETTER KOMI DZJE
1692
+
0508 ; DISALLOWED # CYRILLIC CAPITAL LETTER KOMI LJE
1693
+
0509 ; PVALID # CYRILLIC SMALL LETTER KOMI LJE
1694
+
050A ; DISALLOWED # CYRILLIC CAPITAL LETTER KOMI NJE
1695
+
050B ; PVALID # CYRILLIC SMALL LETTER KOMI NJE
1696
+
050C ; DISALLOWED # CYRILLIC CAPITAL LETTER KOMI SJE
1697
+
050D ; PVALID # CYRILLIC SMALL LETTER KOMI SJE
1698
+
050E ; DISALLOWED # CYRILLIC CAPITAL LETTER KOMI TJE
1699
+
050F ; PVALID # CYRILLIC SMALL LETTER KOMI TJE
1700
+
0510 ; DISALLOWED # CYRILLIC CAPITAL LETTER REVERSED ZE
1701
+
0511 ; PVALID # CYRILLIC SMALL LETTER REVERSED ZE
1702
+
0512 ; DISALLOWED # CYRILLIC CAPITAL LETTER EL WITH HOOK
1703
+
0513 ; PVALID # CYRILLIC SMALL LETTER EL WITH HOOK
1704
+
0514 ; DISALLOWED # CYRILLIC CAPITAL LETTER LHA
1705
+
0515 ; PVALID # CYRILLIC SMALL LETTER LHA
1706
+
0516 ; DISALLOWED # CYRILLIC CAPITAL LETTER RHA
1707
+
0517 ; PVALID # CYRILLIC SMALL LETTER RHA
1708
+
0518 ; DISALLOWED # CYRILLIC CAPITAL LETTER YAE
1709
+
0519 ; PVALID # CYRILLIC SMALL LETTER YAE
1710
+
051A ; DISALLOWED # CYRILLIC CAPITAL LETTER QA
1711
+
051B ; PVALID # CYRILLIC SMALL LETTER QA
1712
+
051C ; DISALLOWED # CYRILLIC CAPITAL LETTER WE
1713
+
051D ; PVALID # CYRILLIC SMALL LETTER WE
1714
+
051E ; DISALLOWED # CYRILLIC CAPITAL LETTER ALEUT KA
1715
+
051F ; PVALID # CYRILLIC SMALL LETTER ALEUT KA
1716
+
0520 ; DISALLOWED # CYRILLIC CAPITAL LETTER EL WITH MIDDLE HOOK
1717
+
0521 ; PVALID # CYRILLIC SMALL LETTER EL WITH MIDDLE HOOK
1718
+
0522 ; DISALLOWED # CYRILLIC CAPITAL LETTER EN WITH MIDDLE HOOK
1719
+
0523 ; PVALID # CYRILLIC SMALL LETTER EN WITH MIDDLE HOOK
1720
+
0524 ; DISALLOWED # CYRILLIC CAPITAL LETTER PE WITH DESCENDER
1721
+
0525 ; PVALID # CYRILLIC SMALL LETTER PE WITH DESCENDER
1722
+
0526..0530 ; UNASSIGNED # <reserved>..<reserved>
1723
+
0531..0556 ; DISALLOWED # ARMENIAN CAPITAL LETTER AYB..ARMENIAN CAPITA
1724
+
0557..0558 ; UNASSIGNED # <reserved>..<reserved>
1725
+
0559 ; PVALID # ARMENIAN MODIFIER LETTER LEFT HALF RING
1726
+
055A..055F ; DISALLOWED # ARMENIAN APOSTROPHE..ARMENIAN ABBREVIATION M
1727
+
0560 ; UNASSIGNED # <reserved>
1728
+
0561..0586 ; PVALID # ARMENIAN SMALL LETTER AYB..ARMENIAN SMALL LE
1729
+
0587 ; DISALLOWED # ARMENIAN SMALL LIGATURE ECH YIWN
1730
+
0588 ; UNASSIGNED # <reserved>
1731
+
0589..058A ; DISALLOWED # ARMENIAN FULL STOP..ARMENIAN HYPHEN
1732
+
058B..0590 ; UNASSIGNED # <reserved>..<reserved>
1733
+
0591..05BD ; PVALID # HEBREW ACCENT ETNAHTA..HEBREW POINT METEG
1734
+
05BE ; DISALLOWED # HEBREW PUNCTUATION MAQAF
1735
+
1736
+
1737
+
1738
+
Faltstrom Standards Track [Page 31]
1739
+
1740
+
RFC 5892 IDNA Code Points August 2010
1741
+
1742
+
1743
+
05BF ; PVALID # HEBREW POINT RAFE
1744
+
05C0 ; DISALLOWED # HEBREW PUNCTUATION PASEQ
1745
+
05C1..05C2 ; PVALID # HEBREW POINT SHIN DOT..HEBREW POINT SIN DOT
1746
+
05C3 ; DISALLOWED # HEBREW PUNCTUATION SOF PASUQ
1747
+
05C4..05C5 ; PVALID # HEBREW MARK UPPER DOT..HEBREW MARK LOWER DOT
1748
+
05C6 ; DISALLOWED # HEBREW PUNCTUATION NUN HAFUKHA
1749
+
05C7 ; PVALID # HEBREW POINT QAMATS QATAN
1750
+
05C8..05CF ; UNASSIGNED # <reserved>..<reserved>
1751
+
05D0..05EA ; PVALID # HEBREW LETTER ALEF..HEBREW LETTER TAV
1752
+
05EB..05EF ; UNASSIGNED # <reserved>..<reserved>
1753
+
05F0..05F2 ; PVALID # HEBREW LIGATURE YIDDISH DOUBLE VAV..HEBREW L
1754
+
05F3..05F4 ; CONTEXTO # HEBREW PUNCTUATION GERESH..HEBREW PUNCTUATIO
1755
+
05F5..05FF ; UNASSIGNED # <reserved>..<reserved>
1756
+
0600..0603 ; DISALLOWED # ARABIC NUMBER SIGN..ARABIC SIGN SAFHA
1757
+
0604..0605 ; UNASSIGNED # <reserved>..<reserved>
1758
+
0606..060F ; DISALLOWED # ARABIC-INDIC CUBE ROOT..ARABIC SIGN MISRA
1759
+
0610..061A ; PVALID # ARABIC SIGN SALLALLAHOU ALAYHE WASSALLAM..AR
1760
+
061B ; DISALLOWED # ARABIC SEMICOLON
1761
+
061C..061D ; UNASSIGNED # <reserved>..<reserved>
1762
+
061E..061F ; DISALLOWED # ARABIC TRIPLE DOT PUNCTUATION MARK..ARABIC Q
1763
+
0620 ; UNASSIGNED # <reserved>
1764
+
0621..063F ; PVALID # ARABIC LETTER HAMZA..ARABIC LETTER FARSI YEH
1765
+
0640 ; DISALLOWED # ARABIC TATWEEL
1766
+
0641..065E ; PVALID # ARABIC LETTER FEH..ARABIC FATHA WITH TWO DOT
1767
+
065F ; UNASSIGNED # <reserved>
1768
+
0660..0669 ; CONTEXTO # ARABIC-INDIC DIGIT ZERO..ARABIC-INDIC DIGIT
1769
+
066A..066D ; DISALLOWED # ARABIC PERCENT SIGN..ARABIC FIVE POINTED STA
1770
+
066E..0674 ; PVALID # ARABIC LETTER DOTLESS BEH..ARABIC LETTER HIG
1771
+
0675..0678 ; DISALLOWED # ARABIC LETTER HIGH HAMZA ALEF..ARABIC LETTER
1772
+
0679..06D3 ; PVALID # ARABIC LETTER TTEH..ARABIC LETTER YEH BARREE
1773
+
06D4 ; DISALLOWED # ARABIC FULL STOP
1774
+
06D5..06DC ; PVALID # ARABIC LETTER AE..ARABIC SMALL HIGH SEEN
1775
+
06DD..06DE ; DISALLOWED # ARABIC END OF AYAH..ARABIC START OF RUB EL H
1776
+
06DF..06E8 ; PVALID # ARABIC SMALL HIGH ROUNDED ZERO..ARABIC SMALL
1777
+
06E9 ; DISALLOWED # ARABIC PLACE OF SAJDAH
1778
+
06EA..06EF ; PVALID # ARABIC EMPTY CENTRE LOW STOP..ARABIC LETTER
1779
+
06F0..06F9 ; CONTEXTO # EXTENDED ARABIC-INDIC DIGIT ZERO..EXTENDED A
1780
+
06FA..06FF ; PVALID # ARABIC LETTER SHEEN WITH DOT BELOW..ARABIC L
1781
+
0700..070D ; DISALLOWED # SYRIAC END OF PARAGRAPH..SYRIAC HARKLEAN AST
1782
+
070E ; UNASSIGNED # <reserved>
1783
+
070F ; DISALLOWED # SYRIAC ABBREVIATION MARK
1784
+
0710..074A ; PVALID # SYRIAC LETTER ALAPH..SYRIAC BARREKH
1785
+
074B..074C ; UNASSIGNED # <reserved>..<reserved>
1786
+
074D..07B1 ; PVALID # SYRIAC LETTER SOGDIAN ZHAIN..THAANA LETTER N
1787
+
07B2..07BF ; UNASSIGNED # <reserved>..<reserved>
1788
+
07C0..07F5 ; PVALID # NKO DIGIT ZERO..NKO LOW TONE APOSTROPHE
1789
+
07F6..07FA ; DISALLOWED # NKO SYMBOL OO DENNEN..NKO LAJANYALAN
1790
+
07FB..07FF ; UNASSIGNED # <reserved>..<reserved>
1791
+
1792
+
1793
+
1794
+
Faltstrom Standards Track [Page 32]
1795
+
1796
+
RFC 5892 IDNA Code Points August 2010
1797
+
1798
+
1799
+
0800..082D ; PVALID # SAMARITAN LETTER ALAF..SAMARITAN MARK NEQUDA
1800
+
082E..082F ; UNASSIGNED # <reserved>..<reserved>
1801
+
0830..083E ; DISALLOWED # SAMARITAN PUNCTUATION NEQUDAA..SAMARITAN PUN
1802
+
083F..08FF ; UNASSIGNED # <reserved>..<reserved>
1803
+
0900..0939 ; PVALID # DEVANAGARI SIGN INVERTED CANDRABINDU..DEVANA
1804
+
093A..093B ; UNASSIGNED # <reserved>..<reserved>
1805
+
093C..094E ; PVALID # DEVANAGARI SIGN NUKTA..DEVANAGARI VOWEL SIGN
1806
+
094F ; UNASSIGNED # <reserved>
1807
+
0950..0955 ; PVALID # DEVANAGARI OM..DEVANAGARI VOWEL SIGN CANDRA
1808
+
0956..0957 ; UNASSIGNED # <reserved>..<reserved>
1809
+
0958..095F ; DISALLOWED # DEVANAGARI LETTER QA..DEVANAGARI LETTER YYA
1810
+
0960..0963 ; PVALID # DEVANAGARI LETTER VOCALIC RR..DEVANAGARI VOW
1811
+
0964..0965 ; DISALLOWED # DEVANAGARI DANDA..DEVANAGARI DOUBLE DANDA
1812
+
0966..096F ; PVALID # DEVANAGARI DIGIT ZERO..DEVANAGARI DIGIT NINE
1813
+
0970 ; DISALLOWED # DEVANAGARI ABBREVIATION SIGN
1814
+
0971..0972 ; PVALID # DEVANAGARI SIGN HIGH SPACING DOT..DEVANAGARI
1815
+
0973..0978 ; UNASSIGNED # <reserved>..<reserved>
1816
+
0979..097F ; PVALID # DEVANAGARI LETTER ZHA..DEVANAGARI LETTER BBA
1817
+
0980 ; UNASSIGNED # <reserved>
1818
+
0981..0983 ; PVALID # BENGALI SIGN CANDRABINDU..BENGALI SIGN VISAR
1819
+
0984 ; UNASSIGNED # <reserved>
1820
+
0985..098C ; PVALID # BENGALI LETTER A..BENGALI LETTER VOCALIC L
1821
+
098D..098E ; UNASSIGNED # <reserved>..<reserved>
1822
+
098F..0990 ; PVALID # BENGALI LETTER E..BENGALI LETTER AI
1823
+
0991..0992 ; UNASSIGNED # <reserved>..<reserved>
1824
+
0993..09A8 ; PVALID # BENGALI LETTER O..BENGALI LETTER NA
1825
+
09A9 ; UNASSIGNED # <reserved>
1826
+
09AA..09B0 ; PVALID # BENGALI LETTER PA..BENGALI LETTER RA
1827
+
09B1 ; UNASSIGNED # <reserved>
1828
+
09B2 ; PVALID # BENGALI LETTER LA
1829
+
09B3..09B5 ; UNASSIGNED # <reserved>..<reserved>
1830
+
09B6..09B9 ; PVALID # BENGALI LETTER SHA..BENGALI LETTER HA
1831
+
09BA..09BB ; UNASSIGNED # <reserved>..<reserved>
1832
+
09BC..09C4 ; PVALID # BENGALI SIGN NUKTA..BENGALI VOWEL SIGN VOCAL
1833
+
09C5..09C6 ; UNASSIGNED # <reserved>..<reserved>
1834
+
09C7..09C8 ; PVALID # BENGALI VOWEL SIGN E..BENGALI VOWEL SIGN AI
1835
+
09C9..09CA ; UNASSIGNED # <reserved>..<reserved>
1836
+
09CB..09CE ; PVALID # BENGALI VOWEL SIGN O..BENGALI LETTER KHANDA
1837
+
09CF..09D6 ; UNASSIGNED # <reserved>..<reserved>
1838
+
09D7 ; PVALID # BENGALI AU LENGTH MARK
1839
+
09D8..09DB ; UNASSIGNED # <reserved>..<reserved>
1840
+
09DC..09DD ; DISALLOWED # BENGALI LETTER RRA..BENGALI LETTER RHA
1841
+
09DE ; UNASSIGNED # <reserved>
1842
+
09DF ; DISALLOWED # BENGALI LETTER YYA
1843
+
09E0..09E3 ; PVALID # BENGALI LETTER VOCALIC RR..BENGALI VOWEL SIG
1844
+
09E4..09E5 ; UNASSIGNED # <reserved>..<reserved>
1845
+
09E6..09F1 ; PVALID # BENGALI DIGIT ZERO..BENGALI LETTER RA WITH L
1846
+
09F2..09FB ; DISALLOWED # BENGALI RUPEE MARK..BENGALI GANDA MARK
1847
+
1848
+
1849
+
1850
+
Faltstrom Standards Track [Page 33]
1851
+
1852
+
RFC 5892 IDNA Code Points August 2010
1853
+
1854
+
1855
+
09FC..0A00 ; UNASSIGNED # <reserved>..<reserved>
1856
+
0A01..0A03 ; PVALID # GURMUKHI SIGN ADAK BINDI..GURMUKHI SIGN VISA
1857
+
0A04 ; UNASSIGNED # <reserved>
1858
+
0A05..0A0A ; PVALID # GURMUKHI LETTER A..GURMUKHI LETTER UU
1859
+
0A0B..0A0E ; UNASSIGNED # <reserved>..<reserved>
1860
+
0A0F..0A10 ; PVALID # GURMUKHI LETTER EE..GURMUKHI LETTER AI
1861
+
0A11..0A12 ; UNASSIGNED # <reserved>..<reserved>
1862
+
0A13..0A28 ; PVALID # GURMUKHI LETTER OO..GURMUKHI LETTER NA
1863
+
0A29 ; UNASSIGNED # <reserved>
1864
+
0A2A..0A30 ; PVALID # GURMUKHI LETTER PA..GURMUKHI LETTER RA
1865
+
0A31 ; UNASSIGNED # <reserved>
1866
+
0A32 ; PVALID # GURMUKHI LETTER LA
1867
+
0A33 ; DISALLOWED # GURMUKHI LETTER LLA
1868
+
0A34 ; UNASSIGNED # <reserved>
1869
+
0A35 ; PVALID # GURMUKHI LETTER VA
1870
+
0A36 ; DISALLOWED # GURMUKHI LETTER SHA
1871
+
0A37 ; UNASSIGNED # <reserved>
1872
+
0A38..0A39 ; PVALID # GURMUKHI LETTER SA..GURMUKHI LETTER HA
1873
+
0A3A..0A3B ; UNASSIGNED # <reserved>..<reserved>
1874
+
0A3C ; PVALID # GURMUKHI SIGN NUKTA
1875
+
0A3D ; UNASSIGNED # <reserved>
1876
+
0A3E..0A42 ; PVALID # GURMUKHI VOWEL SIGN AA..GURMUKHI VOWEL SIGN
1877
+
0A43..0A46 ; UNASSIGNED # <reserved>..<reserved>
1878
+
0A47..0A48 ; PVALID # GURMUKHI VOWEL SIGN EE..GURMUKHI VOWEL SIGN
1879
+
0A49..0A4A ; UNASSIGNED # <reserved>..<reserved>
1880
+
0A4B..0A4D ; PVALID # GURMUKHI VOWEL SIGN OO..GURMUKHI SIGN VIRAMA
1881
+
0A4E..0A50 ; UNASSIGNED # <reserved>..<reserved>
1882
+
0A51 ; PVALID # GURMUKHI SIGN UDAAT
1883
+
0A52..0A58 ; UNASSIGNED # <reserved>..<reserved>
1884
+
0A59..0A5B ; DISALLOWED # GURMUKHI LETTER KHHA..GURMUKHI LETTER ZA
1885
+
0A5C ; PVALID # GURMUKHI LETTER RRA
1886
+
0A5D ; UNASSIGNED # <reserved>
1887
+
0A5E ; DISALLOWED # GURMUKHI LETTER FA
1888
+
0A5F..0A65 ; UNASSIGNED # <reserved>..<reserved>
1889
+
0A66..0A75 ; PVALID # GURMUKHI DIGIT ZERO..GURMUKHI SIGN YAKASH
1890
+
0A76..0A80 ; UNASSIGNED # <reserved>..<reserved>
1891
+
0A81..0A83 ; PVALID # GUJARATI SIGN CANDRABINDU..GUJARATI SIGN VIS
1892
+
0A84 ; UNASSIGNED # <reserved>
1893
+
0A85..0A8D ; PVALID # GUJARATI LETTER A..GUJARATI VOWEL CANDRA E
1894
+
0A8E ; UNASSIGNED # <reserved>
1895
+
0A8F..0A91 ; PVALID # GUJARATI LETTER E..GUJARATI VOWEL CANDRA O
1896
+
0A92 ; UNASSIGNED # <reserved>
1897
+
0A93..0AA8 ; PVALID # GUJARATI LETTER O..GUJARATI LETTER NA
1898
+
0AA9 ; UNASSIGNED # <reserved>
1899
+
0AAA..0AB0 ; PVALID # GUJARATI LETTER PA..GUJARATI LETTER RA
1900
+
0AB1 ; UNASSIGNED # <reserved>
1901
+
0AB2..0AB3 ; PVALID # GUJARATI LETTER LA..GUJARATI LETTER LLA
1902
+
0AB4 ; UNASSIGNED # <reserved>
1903
+
1904
+
1905
+
1906
+
Faltstrom Standards Track [Page 34]
1907
+
1908
+
RFC 5892 IDNA Code Points August 2010
1909
+
1910
+
1911
+
0AB5..0AB9 ; PVALID # GUJARATI LETTER VA..GUJARATI LETTER HA
1912
+
0ABA..0ABB ; UNASSIGNED # <reserved>..<reserved>
1913
+
0ABC..0AC5 ; PVALID # GUJARATI SIGN NUKTA..GUJARATI VOWEL SIGN CAN
1914
+
0AC6 ; UNASSIGNED # <reserved>
1915
+
0AC7..0AC9 ; PVALID # GUJARATI VOWEL SIGN E..GUJARATI VOWEL SIGN C
1916
+
0ACA ; UNASSIGNED # <reserved>
1917
+
0ACB..0ACD ; PVALID # GUJARATI VOWEL SIGN O..GUJARATI SIGN VIRAMA
1918
+
0ACE..0ACF ; UNASSIGNED # <reserved>..<reserved>
1919
+
0AD0 ; PVALID # GUJARATI OM
1920
+
0AD1..0ADF ; UNASSIGNED # <reserved>..<reserved>
1921
+
0AE0..0AE3 ; PVALID # GUJARATI LETTER VOCALIC RR..GUJARATI VOWEL S
1922
+
0AE4..0AE5 ; UNASSIGNED # <reserved>..<reserved>
1923
+
0AE6..0AEF ; PVALID # GUJARATI DIGIT ZERO..GUJARATI DIGIT NINE
1924
+
0AF0 ; UNASSIGNED # <reserved>
1925
+
0AF1 ; DISALLOWED # GUJARATI RUPEE SIGN
1926
+
0AF2..0B00 ; UNASSIGNED # <reserved>..<reserved>
1927
+
0B01..0B03 ; PVALID # ORIYA SIGN CANDRABINDU..ORIYA SIGN VISARGA
1928
+
0B04 ; UNASSIGNED # <reserved>
1929
+
0B05..0B0C ; PVALID # ORIYA LETTER A..ORIYA LETTER VOCALIC L
1930
+
0B0D..0B0E ; UNASSIGNED # <reserved>..<reserved>
1931
+
0B0F..0B10 ; PVALID # ORIYA LETTER E..ORIYA LETTER AI
1932
+
0B11..0B12 ; UNASSIGNED # <reserved>..<reserved>
1933
+
0B13..0B28 ; PVALID # ORIYA LETTER O..ORIYA LETTER NA
1934
+
0B29 ; UNASSIGNED # <reserved>
1935
+
0B2A..0B30 ; PVALID # ORIYA LETTER PA..ORIYA LETTER RA
1936
+
0B31 ; UNASSIGNED # <reserved>
1937
+
0B32..0B33 ; PVALID # ORIYA LETTER LA..ORIYA LETTER LLA
1938
+
0B34 ; UNASSIGNED # <reserved>
1939
+
0B35..0B39 ; PVALID # ORIYA LETTER VA..ORIYA LETTER HA
1940
+
0B3A..0B3B ; UNASSIGNED # <reserved>..<reserved>
1941
+
0B3C..0B44 ; PVALID # ORIYA SIGN NUKTA..ORIYA VOWEL SIGN VOCALIC R
1942
+
0B45..0B46 ; UNASSIGNED # <reserved>..<reserved>
1943
+
0B47..0B48 ; PVALID # ORIYA VOWEL SIGN E..ORIYA VOWEL SIGN AI
1944
+
0B49..0B4A ; UNASSIGNED # <reserved>..<reserved>
1945
+
0B4B..0B4D ; PVALID # ORIYA VOWEL SIGN O..ORIYA SIGN VIRAMA
1946
+
0B4E..0B55 ; UNASSIGNED # <reserved>..<reserved>
1947
+
0B56..0B57 ; PVALID # ORIYA AI LENGTH MARK..ORIYA AU LENGTH MARK
1948
+
0B58..0B5B ; UNASSIGNED # <reserved>..<reserved>
1949
+
0B5C..0B5D ; DISALLOWED # ORIYA LETTER RRA..ORIYA LETTER RHA
1950
+
0B5E ; UNASSIGNED # <reserved>
1951
+
0B5F..0B63 ; PVALID # ORIYA LETTER YYA..ORIYA VOWEL SIGN VOCALIC L
1952
+
0B64..0B65 ; UNASSIGNED # <reserved>..<reserved>
1953
+
0B66..0B6F ; PVALID # ORIYA DIGIT ZERO..ORIYA DIGIT NINE
1954
+
0B70 ; DISALLOWED # ORIYA ISSHAR
1955
+
0B71 ; PVALID # ORIYA LETTER WA
1956
+
0B72..0B81 ; UNASSIGNED # <reserved>..<reserved>
1957
+
0B82..0B83 ; PVALID # TAMIL SIGN ANUSVARA..TAMIL SIGN VISARGA
1958
+
0B84 ; UNASSIGNED # <reserved>
1959
+
1960
+
1961
+
1962
+
Faltstrom Standards Track [Page 35]
1963
+
1964
+
RFC 5892 IDNA Code Points August 2010
1965
+
1966
+
1967
+
0B85..0B8A ; PVALID # TAMIL LETTER A..TAMIL LETTER UU
1968
+
0B8B..0B8D ; UNASSIGNED # <reserved>..<reserved>
1969
+
0B8E..0B90 ; PVALID # TAMIL LETTER E..TAMIL LETTER AI
1970
+
0B91 ; UNASSIGNED # <reserved>
1971
+
0B92..0B95 ; PVALID # TAMIL LETTER O..TAMIL LETTER KA
1972
+
0B96..0B98 ; UNASSIGNED # <reserved>..<reserved>
1973
+
0B99..0B9A ; PVALID # TAMIL LETTER NGA..TAMIL LETTER CA
1974
+
0B9B ; UNASSIGNED # <reserved>
1975
+
0B9C ; PVALID # TAMIL LETTER JA
1976
+
0B9D ; UNASSIGNED # <reserved>
1977
+
0B9E..0B9F ; PVALID # TAMIL LETTER NYA..TAMIL LETTER TTA
1978
+
0BA0..0BA2 ; UNASSIGNED # <reserved>..<reserved>
1979
+
0BA3..0BA4 ; PVALID # TAMIL LETTER NNA..TAMIL LETTER TA
1980
+
0BA5..0BA7 ; UNASSIGNED # <reserved>..<reserved>
1981
+
0BA8..0BAA ; PVALID # TAMIL LETTER NA..TAMIL LETTER PA
1982
+
0BAB..0BAD ; UNASSIGNED # <reserved>..<reserved>
1983
+
0BAE..0BB9 ; PVALID # TAMIL LETTER MA..TAMIL LETTER HA
1984
+
0BBA..0BBD ; UNASSIGNED # <reserved>..<reserved>
1985
+
0BBE..0BC2 ; PVALID # TAMIL VOWEL SIGN AA..TAMIL VOWEL SIGN UU
1986
+
0BC3..0BC5 ; UNASSIGNED # <reserved>..<reserved>
1987
+
0BC6..0BC8 ; PVALID # TAMIL VOWEL SIGN E..TAMIL VOWEL SIGN AI
1988
+
0BC9 ; UNASSIGNED # <reserved>
1989
+
0BCA..0BCD ; PVALID # TAMIL VOWEL SIGN O..TAMIL SIGN VIRAMA
1990
+
0BCE..0BCF ; UNASSIGNED # <reserved>..<reserved>
1991
+
0BD0 ; PVALID # TAMIL OM
1992
+
0BD1..0BD6 ; UNASSIGNED # <reserved>..<reserved>
1993
+
0BD7 ; PVALID # TAMIL AU LENGTH MARK
1994
+
0BD8..0BE5 ; UNASSIGNED # <reserved>..<reserved>
1995
+
0BE6..0BEF ; PVALID # TAMIL DIGIT ZERO..TAMIL DIGIT NINE
1996
+
0BF0..0BFA ; DISALLOWED # TAMIL NUMBER TEN..TAMIL NUMBER SIGN
1997
+
0BFB..0C00 ; UNASSIGNED # <reserved>..<reserved>
1998
+
0C01..0C03 ; PVALID # TELUGU SIGN CANDRABINDU..TELUGU SIGN VISARGA
1999
+
0C04 ; UNASSIGNED # <reserved>
2000
+
0C05..0C0C ; PVALID # TELUGU LETTER A..TELUGU LETTER VOCALIC L
2001
+
0C0D ; UNASSIGNED # <reserved>
2002
+
0C0E..0C10 ; PVALID # TELUGU LETTER E..TELUGU LETTER AI
2003
+
0C11 ; UNASSIGNED # <reserved>
2004
+
0C12..0C28 ; PVALID # TELUGU LETTER O..TELUGU LETTER NA
2005
+
0C29 ; UNASSIGNED # <reserved>
2006
+
0C2A..0C33 ; PVALID # TELUGU LETTER PA..TELUGU LETTER LLA
2007
+
0C34 ; UNASSIGNED # <reserved>
2008
+
0C35..0C39 ; PVALID # TELUGU LETTER VA..TELUGU LETTER HA
2009
+
0C3A..0C3C ; UNASSIGNED # <reserved>..<reserved>
2010
+
0C3D..0C44 ; PVALID # TELUGU SIGN AVAGRAHA..TELUGU VOWEL SIGN VOCA
2011
+
0C45 ; UNASSIGNED # <reserved>
2012
+
0C46..0C48 ; PVALID # TELUGU VOWEL SIGN E..TELUGU VOWEL SIGN AI
2013
+
0C49 ; UNASSIGNED # <reserved>
2014
+
0C4A..0C4D ; PVALID # TELUGU VOWEL SIGN O..TELUGU SIGN VIRAMA
2015
+
2016
+
2017
+
2018
+
Faltstrom Standards Track [Page 36]
2019
+
2020
+
RFC 5892 IDNA Code Points August 2010
2021
+
2022
+
2023
+
0C4E..0C54 ; UNASSIGNED # <reserved>..<reserved>
2024
+
0C55..0C56 ; PVALID # TELUGU LENGTH MARK..TELUGU AI LENGTH MARK
2025
+
0C57 ; UNASSIGNED # <reserved>
2026
+
0C58..0C59 ; PVALID # TELUGU LETTER TSA..TELUGU LETTER DZA
2027
+
0C5A..0C5F ; UNASSIGNED # <reserved>..<reserved>
2028
+
0C60..0C63 ; PVALID # TELUGU LETTER VOCALIC RR..TELUGU VOWEL SIGN
2029
+
0C64..0C65 ; UNASSIGNED # <reserved>..<reserved>
2030
+
0C66..0C6F ; PVALID # TELUGU DIGIT ZERO..TELUGU DIGIT NINE
2031
+
0C70..0C77 ; UNASSIGNED # <reserved>..<reserved>
2032
+
0C78..0C7F ; DISALLOWED # TELUGU FRACTION DIGIT ZERO FOR ODD POWERS OF
2033
+
0C80..0C81 ; UNASSIGNED # <reserved>..<reserved>
2034
+
0C82..0C83 ; PVALID # KANNADA SIGN ANUSVARA..KANNADA SIGN VISARGA
2035
+
0C84 ; UNASSIGNED # <reserved>
2036
+
0C85..0C8C ; PVALID # KANNADA LETTER A..KANNADA LETTER VOCALIC L
2037
+
0C8D ; UNASSIGNED # <reserved>
2038
+
0C8E..0C90 ; PVALID # KANNADA LETTER E..KANNADA LETTER AI
2039
+
0C91 ; UNASSIGNED # <reserved>
2040
+
0C92..0CA8 ; PVALID # KANNADA LETTER O..KANNADA LETTER NA
2041
+
0CA9 ; UNASSIGNED # <reserved>
2042
+
0CAA..0CB3 ; PVALID # KANNADA LETTER PA..KANNADA LETTER LLA
2043
+
0CB4 ; UNASSIGNED # <reserved>
2044
+
0CB5..0CB9 ; PVALID # KANNADA LETTER VA..KANNADA LETTER HA
2045
+
0CBA..0CBB ; UNASSIGNED # <reserved>..<reserved>
2046
+
0CBC..0CC4 ; PVALID # KANNADA SIGN NUKTA..KANNADA VOWEL SIGN VOCAL
2047
+
0CC5 ; UNASSIGNED # <reserved>
2048
+
0CC6..0CC8 ; PVALID # KANNADA VOWEL SIGN E..KANNADA VOWEL SIGN AI
2049
+
0CC9 ; UNASSIGNED # <reserved>
2050
+
0CCA..0CCD ; PVALID # KANNADA VOWEL SIGN O..KANNADA SIGN VIRAMA
2051
+
0CCE..0CD4 ; UNASSIGNED # <reserved>..<reserved>
2052
+
0CD5..0CD6 ; PVALID # KANNADA LENGTH MARK..KANNADA AI LENGTH MARK
2053
+
0CD7..0CDD ; UNASSIGNED # <reserved>..<reserved>
2054
+
0CDE ; PVALID # KANNADA LETTER FA
2055
+
0CDF ; UNASSIGNED # <reserved>
2056
+
0CE0..0CE3 ; PVALID # KANNADA LETTER VOCALIC RR..KANNADA VOWEL SIG
2057
+
0CE4..0CE5 ; UNASSIGNED # <reserved>..<reserved>
2058
+
0CE6..0CEF ; PVALID # KANNADA DIGIT ZERO..KANNADA DIGIT NINE
2059
+
0CF0 ; UNASSIGNED # <reserved>
2060
+
0CF1..0CF2 ; DISALLOWED # KANNADA SIGN JIHVAMULIYA..KANNADA SIGN UPADH
2061
+
0CF3..0D01 ; UNASSIGNED # <reserved>..<reserved>
2062
+
0D02..0D03 ; PVALID # MALAYALAM SIGN ANUSVARA..MALAYALAM SIGN VISA
2063
+
0D04 ; UNASSIGNED # <reserved>
2064
+
0D05..0D0C ; PVALID # MALAYALAM LETTER A..MALAYALAM LETTER VOCALIC
2065
+
0D0D ; UNASSIGNED # <reserved>
2066
+
0D0E..0D10 ; PVALID # MALAYALAM LETTER E..MALAYALAM LETTER AI
2067
+
0D11 ; UNASSIGNED # <reserved>
2068
+
0D12..0D28 ; PVALID # MALAYALAM LETTER O..MALAYALAM LETTER NA
2069
+
0D29 ; UNASSIGNED # <reserved>
2070
+
0D2A..0D39 ; PVALID # MALAYALAM LETTER PA..MALAYALAM LETTER HA
2071
+
2072
+
2073
+
2074
+
Faltstrom Standards Track [Page 37]
2075
+
2076
+
RFC 5892 IDNA Code Points August 2010
2077
+
2078
+
2079
+
0D3A..0D3C ; UNASSIGNED # <reserved>..<reserved>
2080
+
0D3D..0D44 ; PVALID # MALAYALAM SIGN AVAGRAHA..MALAYALAM VOWEL SIG
2081
+
0D45 ; UNASSIGNED # <reserved>
2082
+
0D46..0D48 ; PVALID # MALAYALAM VOWEL SIGN E..MALAYALAM VOWEL SIGN
2083
+
0D49 ; UNASSIGNED # <reserved>
2084
+
0D4A..0D4D ; PVALID # MALAYALAM VOWEL SIGN O..MALAYALAM SIGN VIRAM
2085
+
0D4E..0D56 ; UNASSIGNED # <reserved>..<reserved>
2086
+
0D57 ; PVALID # MALAYALAM AU LENGTH MARK
2087
+
0D58..0D5F ; UNASSIGNED # <reserved>..<reserved>
2088
+
0D60..0D63 ; PVALID # MALAYALAM LETTER VOCALIC RR..MALAYALAM VOWEL
2089
+
0D64..0D65 ; UNASSIGNED # <reserved>..<reserved>
2090
+
0D66..0D6F ; PVALID # MALAYALAM DIGIT ZERO..MALAYALAM DIGIT NINE
2091
+
0D70..0D75 ; DISALLOWED # MALAYALAM NUMBER TEN..MALAYALAM FRACTION THR
2092
+
0D76..0D78 ; UNASSIGNED # <reserved>..<reserved>
2093
+
0D79 ; DISALLOWED # MALAYALAM DATE MARK
2094
+
0D7A..0D7F ; PVALID # MALAYALAM LETTER CHILLU NN..MALAYALAM LETTER
2095
+
0D80..0D81 ; UNASSIGNED # <reserved>..<reserved>
2096
+
0D82..0D83 ; PVALID # SINHALA SIGN ANUSVARAYA..SINHALA SIGN VISARG
2097
+
0D84 ; UNASSIGNED # <reserved>
2098
+
0D85..0D96 ; PVALID # SINHALA LETTER AYANNA..SINHALA LETTER AUYANN
2099
+
0D97..0D99 ; UNASSIGNED # <reserved>..<reserved>
2100
+
0D9A..0DB1 ; PVALID # SINHALA LETTER ALPAPRAANA KAYANNA..SINHALA L
2101
+
0DB2 ; UNASSIGNED # <reserved>
2102
+
0DB3..0DBB ; PVALID # SINHALA LETTER SANYAKA DAYANNA..SINHALA LETT
2103
+
0DBC ; UNASSIGNED # <reserved>
2104
+
0DBD ; PVALID # SINHALA LETTER DANTAJA LAYANNA
2105
+
0DBE..0DBF ; UNASSIGNED # <reserved>..<reserved>
2106
+
0DC0..0DC6 ; PVALID # SINHALA LETTER VAYANNA..SINHALA LETTER FAYAN
2107
+
0DC7..0DC9 ; UNASSIGNED # <reserved>..<reserved>
2108
+
0DCA ; PVALID # SINHALA SIGN AL-LAKUNA
2109
+
0DCB..0DCE ; UNASSIGNED # <reserved>..<reserved>
2110
+
0DCF..0DD4 ; PVALID # SINHALA VOWEL SIGN AELA-PILLA..SINHALA VOWEL
2111
+
0DD5 ; UNASSIGNED # <reserved>
2112
+
0DD6 ; PVALID # SINHALA VOWEL SIGN DIGA PAA-PILLA
2113
+
0DD7 ; UNASSIGNED # <reserved>
2114
+
0DD8..0DDF ; PVALID # SINHALA VOWEL SIGN GAETTA-PILLA..SINHALA VOW
2115
+
0DE0..0DF1 ; UNASSIGNED # <reserved>..<reserved>
2116
+
0DF2..0DF3 ; PVALID # SINHALA VOWEL SIGN DIGA GAETTA-PILLA..SINHAL
2117
+
0DF4 ; DISALLOWED # SINHALA PUNCTUATION KUNDDALIYA
2118
+
0DF5..0E00 ; UNASSIGNED # <reserved>..<reserved>
2119
+
0E01..0E32 ; PVALID # THAI CHARACTER KO KAI..THAI CHARACTER SARA A
2120
+
0E33 ; DISALLOWED # THAI CHARACTER SARA AM
2121
+
0E34..0E3A ; PVALID # THAI CHARACTER SARA I..THAI CHARACTER PHINTH
2122
+
0E3B..0E3E ; UNASSIGNED # <reserved>..<reserved>
2123
+
0E3F ; DISALLOWED # THAI CURRENCY SYMBOL BAHT
2124
+
0E40..0E4E ; PVALID # THAI CHARACTER SARA E..THAI CHARACTER YAMAKK
2125
+
0E4F ; DISALLOWED # THAI CHARACTER FONGMAN
2126
+
0E50..0E59 ; PVALID # THAI DIGIT ZERO..THAI DIGIT NINE
2127
+
2128
+
2129
+
2130
+
Faltstrom Standards Track [Page 38]
2131
+
2132
+
RFC 5892 IDNA Code Points August 2010
2133
+
2134
+
2135
+
0E5A..0E5B ; DISALLOWED # THAI CHARACTER ANGKHANKHU..THAI CHARACTER KH
2136
+
0E5C..0E80 ; UNASSIGNED # <reserved>..<reserved>
2137
+
0E81..0E82 ; PVALID # LAO LETTER KO..LAO LETTER KHO SUNG
2138
+
0E83 ; UNASSIGNED # <reserved>
2139
+
0E84 ; PVALID # LAO LETTER KHO TAM
2140
+
0E85..0E86 ; UNASSIGNED # <reserved>..<reserved>
2141
+
0E87..0E88 ; PVALID # LAO LETTER NGO..LAO LETTER CO
2142
+
0E89 ; UNASSIGNED # <reserved>
2143
+
0E8A ; PVALID # LAO LETTER SO TAM
2144
+
0E8B..0E8C ; UNASSIGNED # <reserved>..<reserved>
2145
+
0E8D ; PVALID # LAO LETTER NYO
2146
+
0E8E..0E93 ; UNASSIGNED # <reserved>..<reserved>
2147
+
0E94..0E97 ; PVALID # LAO LETTER DO..LAO LETTER THO TAM
2148
+
0E98 ; UNASSIGNED # <reserved>
2149
+
0E99..0E9F ; PVALID # LAO LETTER NO..LAO LETTER FO SUNG
2150
+
0EA0 ; UNASSIGNED # <reserved>
2151
+
0EA1..0EA3 ; PVALID # LAO LETTER MO..LAO LETTER LO LING
2152
+
0EA4 ; UNASSIGNED # <reserved>
2153
+
0EA5 ; PVALID # LAO LETTER LO LOOT
2154
+
0EA6 ; UNASSIGNED # <reserved>
2155
+
0EA7 ; PVALID # LAO LETTER WO
2156
+
0EA8..0EA9 ; UNASSIGNED # <reserved>..<reserved>
2157
+
0EAA..0EAB ; PVALID # LAO LETTER SO SUNG..LAO LETTER HO SUNG
2158
+
0EAC ; UNASSIGNED # <reserved>
2159
+
0EAD..0EB2 ; PVALID # LAO LETTER O..LAO VOWEL SIGN AA
2160
+
0EB3 ; DISALLOWED # LAO VOWEL SIGN AM
2161
+
0EB4..0EB9 ; PVALID # LAO VOWEL SIGN I..LAO VOWEL SIGN UU
2162
+
0EBA ; UNASSIGNED # <reserved>
2163
+
0EBB..0EBD ; PVALID # LAO VOWEL SIGN MAI KON..LAO SEMIVOWEL SIGN N
2164
+
0EBE..0EBF ; UNASSIGNED # <reserved>..<reserved>
2165
+
0EC0..0EC4 ; PVALID # LAO VOWEL SIGN E..LAO VOWEL SIGN AI
2166
+
0EC5 ; UNASSIGNED # <reserved>
2167
+
0EC6 ; PVALID # LAO KO LA
2168
+
0EC7 ; UNASSIGNED # <reserved>
2169
+
0EC8..0ECD ; PVALID # LAO TONE MAI EK..LAO NIGGAHITA
2170
+
0ECE..0ECF ; UNASSIGNED # <reserved>..<reserved>
2171
+
0ED0..0ED9 ; PVALID # LAO DIGIT ZERO..LAO DIGIT NINE
2172
+
0EDA..0EDB ; UNASSIGNED # <reserved>..<reserved>
2173
+
0EDC..0EDD ; DISALLOWED # LAO HO NO..LAO HO MO
2174
+
0EDE..0EFF ; UNASSIGNED # <reserved>..<reserved>
2175
+
0F00 ; PVALID # TIBETAN SYLLABLE OM
2176
+
0F01..0F0A ; DISALLOWED # TIBETAN MARK GTER YIG MGO TRUNCATED A..TIBET
2177
+
0F0B ; PVALID # TIBETAN MARK INTERSYLLABIC TSHEG
2178
+
0F0C..0F17 ; DISALLOWED # TIBETAN MARK DELIMITER TSHEG BSTAR..TIBETAN
2179
+
0F18..0F19 ; PVALID # TIBETAN ASTROLOGICAL SIGN -KHYUD PA..TIBETAN
2180
+
0F1A..0F1F ; DISALLOWED # TIBETAN SIGN RDEL DKAR GCIG..TIBETAN SIGN RD
2181
+
0F20..0F29 ; PVALID # TIBETAN DIGIT ZERO..TIBETAN DIGIT NINE
2182
+
0F2A..0F34 ; DISALLOWED # TIBETAN DIGIT HALF ONE..TIBETAN MARK BSDUS R
2183
+
2184
+
2185
+
2186
+
Faltstrom Standards Track [Page 39]
2187
+
2188
+
RFC 5892 IDNA Code Points August 2010
2189
+
2190
+
2191
+
0F35 ; PVALID # TIBETAN MARK NGAS BZUNG NYI ZLA
2192
+
0F36 ; DISALLOWED # TIBETAN MARK CARET -DZUD RTAGS BZHI MIG CAN
2193
+
0F37 ; PVALID # TIBETAN MARK NGAS BZUNG SGOR RTAGS
2194
+
0F38 ; DISALLOWED # TIBETAN MARK CHE MGO
2195
+
0F39 ; PVALID # TIBETAN MARK TSA -PHRU
2196
+
0F3A..0F3D ; DISALLOWED # TIBETAN MARK GUG RTAGS GYON..TIBETAN MARK AN
2197
+
0F3E..0F42 ; PVALID # TIBETAN SIGN YAR TSHES..TIBETAN LETTER GA
2198
+
0F43 ; DISALLOWED # TIBETAN LETTER GHA
2199
+
0F44..0F47 ; PVALID # TIBETAN LETTER NGA..TIBETAN LETTER JA
2200
+
0F48 ; UNASSIGNED # <reserved>
2201
+
0F49..0F4C ; PVALID # TIBETAN LETTER NYA..TIBETAN LETTER DDA
2202
+
0F4D ; DISALLOWED # TIBETAN LETTER DDHA
2203
+
0F4E..0F51 ; PVALID # TIBETAN LETTER NNA..TIBETAN LETTER DA
2204
+
0F52 ; DISALLOWED # TIBETAN LETTER DHA
2205
+
0F53..0F56 ; PVALID # TIBETAN LETTER NA..TIBETAN LETTER BA
2206
+
0F57 ; DISALLOWED # TIBETAN LETTER BHA
2207
+
0F58..0F5B ; PVALID # TIBETAN LETTER MA..TIBETAN LETTER DZA
2208
+
0F5C ; DISALLOWED # TIBETAN LETTER DZHA
2209
+
0F5D..0F68 ; PVALID # TIBETAN LETTER WA..TIBETAN LETTER A
2210
+
0F69 ; DISALLOWED # TIBETAN LETTER KSSA
2211
+
0F6A..0F6C ; PVALID # TIBETAN LETTER FIXED-FORM RA..TIBETAN LETTER
2212
+
0F6D..0F70 ; UNASSIGNED # <reserved>..<reserved>
2213
+
0F71..0F72 ; PVALID # TIBETAN VOWEL SIGN AA..TIBETAN VOWEL SIGN I
2214
+
0F73 ; DISALLOWED # TIBETAN VOWEL SIGN II
2215
+
0F74 ; PVALID # TIBETAN VOWEL SIGN U
2216
+
0F75..0F79 ; DISALLOWED # TIBETAN VOWEL SIGN UU..TIBETAN VOWEL SIGN VO
2217
+
0F7A..0F80 ; PVALID # TIBETAN VOWEL SIGN E..TIBETAN VOWEL SIGN REV
2218
+
0F81 ; DISALLOWED # TIBETAN VOWEL SIGN REVERSED II
2219
+
0F82..0F84 ; PVALID # TIBETAN SIGN NYI ZLA NAA DA..TIBETAN MARK HA
2220
+
0F85 ; DISALLOWED # TIBETAN MARK PALUTA
2221
+
0F86..0F8B ; PVALID # TIBETAN SIGN LCI RTAGS..TIBETAN SIGN GRU MED
2222
+
0F8C..0F8F ; UNASSIGNED # <reserved>..<reserved>
2223
+
0F90..0F92 ; PVALID # TIBETAN SUBJOINED LETTER KA..TIBETAN SUBJOIN
2224
+
0F93 ; DISALLOWED # TIBETAN SUBJOINED LETTER GHA
2225
+
0F94..0F97 ; PVALID # TIBETAN SUBJOINED LETTER NGA..TIBETAN SUBJOI
2226
+
0F98 ; UNASSIGNED # <reserved>
2227
+
0F99..0F9C ; PVALID # TIBETAN SUBJOINED LETTER NYA..TIBETAN SUBJOI
2228
+
0F9D ; DISALLOWED # TIBETAN SUBJOINED LETTER DDHA
2229
+
0F9E..0FA1 ; PVALID # TIBETAN SUBJOINED LETTER NNA..TIBETAN SUBJOI
2230
+
0FA2 ; DISALLOWED # TIBETAN SUBJOINED LETTER DHA
2231
+
0FA3..0FA6 ; PVALID # TIBETAN SUBJOINED LETTER NA..TIBETAN SUBJOIN
2232
+
0FA7 ; DISALLOWED # TIBETAN SUBJOINED LETTER BHA
2233
+
0FA8..0FAB ; PVALID # TIBETAN SUBJOINED LETTER MA..TIBETAN SUBJOIN
2234
+
0FAC ; DISALLOWED # TIBETAN SUBJOINED LETTER DZHA
2235
+
0FAD..0FB8 ; PVALID # TIBETAN SUBJOINED LETTER WA..TIBETAN SUBJOIN
2236
+
0FB9 ; DISALLOWED # TIBETAN SUBJOINED LETTER KSSA
2237
+
0FBA..0FBC ; PVALID # TIBETAN SUBJOINED LETTER FIXED-FORM WA..TIBE
2238
+
0FBD ; UNASSIGNED # <reserved>
2239
+
2240
+
2241
+
2242
+
Faltstrom Standards Track [Page 40]
2243
+
2244
+
RFC 5892 IDNA Code Points August 2010
2245
+
2246
+
2247
+
0FBE..0FC5 ; DISALLOWED # TIBETAN KU RU KHA..TIBETAN SYMBOL RDO RJE
2248
+
0FC6 ; PVALID # TIBETAN SYMBOL PADMA GDAN
2249
+
0FC7..0FCC ; DISALLOWED # TIBETAN SYMBOL RDO RJE RGYA GRAM..TIBETAN SY
2250
+
0FCD ; UNASSIGNED # <reserved>
2251
+
0FCE..0FD8 ; DISALLOWED # TIBETAN SIGN RDEL NAG RDEL DKAR..LEFT-FACING
2252
+
0FD9..0FFF ; UNASSIGNED # <reserved>..<reserved>
2253
+
1000..1049 ; PVALID # MYANMAR LETTER KA..MYANMAR DIGIT NINE
2254
+
104A..104F ; DISALLOWED # MYANMAR SIGN LITTLE SECTION..MYANMAR SYMBOL
2255
+
1050..109D ; PVALID # MYANMAR LETTER SHA..MYANMAR VOWEL SIGN AITON
2256
+
109E..10C5 ; DISALLOWED # MYANMAR SYMBOL SHAN ONE..GEORGIAN CAPITAL LE
2257
+
10C6..10CF ; UNASSIGNED # <reserved>..<reserved>
2258
+
10D0..10FA ; PVALID # GEORGIAN LETTER AN..GEORGIAN LETTER AIN
2259
+
10FB..10FC ; DISALLOWED # GEORGIAN PARAGRAPH SEPARATOR..MODIFIER LETTE
2260
+
10FD..10FF ; UNASSIGNED # <reserved>..<reserved>
2261
+
1100..11FF ; DISALLOWED # HANGUL CHOSEONG KIYEOK..HANGUL JONGSEONG SSA
2262
+
1200..1248 ; PVALID # ETHIOPIC SYLLABLE HA..ETHIOPIC SYLLABLE QWA
2263
+
1249 ; UNASSIGNED # <reserved>
2264
+
124A..124D ; PVALID # ETHIOPIC SYLLABLE QWI..ETHIOPIC SYLLABLE QWE
2265
+
124E..124F ; UNASSIGNED # <reserved>..<reserved>
2266
+
1250..1256 ; PVALID # ETHIOPIC SYLLABLE QHA..ETHIOPIC SYLLABLE QHO
2267
+
1257 ; UNASSIGNED # <reserved>
2268
+
1258 ; PVALID # ETHIOPIC SYLLABLE QHWA
2269
+
1259 ; UNASSIGNED # <reserved>
2270
+
125A..125D ; PVALID # ETHIOPIC SYLLABLE QHWI..ETHIOPIC SYLLABLE QH
2271
+
125E..125F ; UNASSIGNED # <reserved>..<reserved>
2272
+
1260..1288 ; PVALID # ETHIOPIC SYLLABLE BA..ETHIOPIC SYLLABLE XWA
2273
+
1289 ; UNASSIGNED # <reserved>
2274
+
128A..128D ; PVALID # ETHIOPIC SYLLABLE XWI..ETHIOPIC SYLLABLE XWE
2275
+
128E..128F ; UNASSIGNED # <reserved>..<reserved>
2276
+
1290..12B0 ; PVALID # ETHIOPIC SYLLABLE NA..ETHIOPIC SYLLABLE KWA
2277
+
12B1 ; UNASSIGNED # <reserved>
2278
+
12B2..12B5 ; PVALID # ETHIOPIC SYLLABLE KWI..ETHIOPIC SYLLABLE KWE
2279
+
12B6..12B7 ; UNASSIGNED # <reserved>..<reserved>
2280
+
12B8..12BE ; PVALID # ETHIOPIC SYLLABLE KXA..ETHIOPIC SYLLABLE KXO
2281
+
12BF ; UNASSIGNED # <reserved>
2282
+
12C0 ; PVALID # ETHIOPIC SYLLABLE KXWA
2283
+
12C1 ; UNASSIGNED # <reserved>
2284
+
12C2..12C5 ; PVALID # ETHIOPIC SYLLABLE KXWI..ETHIOPIC SYLLABLE KX
2285
+
12C6..12C7 ; UNASSIGNED # <reserved>..<reserved>
2286
+
12C8..12D6 ; PVALID # ETHIOPIC SYLLABLE WA..ETHIOPIC SYLLABLE PHAR
2287
+
12D7 ; UNASSIGNED # <reserved>
2288
+
12D8..1310 ; PVALID # ETHIOPIC SYLLABLE ZA..ETHIOPIC SYLLABLE GWA
2289
+
1311 ; UNASSIGNED # <reserved>
2290
+
1312..1315 ; PVALID # ETHIOPIC SYLLABLE GWI..ETHIOPIC SYLLABLE GWE
2291
+
1316..1317 ; UNASSIGNED # <reserved>..<reserved>
2292
+
1318..135A ; PVALID # ETHIOPIC SYLLABLE GGA..ETHIOPIC SYLLABLE FYA
2293
+
135B..135E ; UNASSIGNED # <reserved>..<reserved>
2294
+
135F ; PVALID # ETHIOPIC COMBINING GEMINATION MARK
2295
+
2296
+
2297
+
2298
+
Faltstrom Standards Track [Page 41]
2299
+
2300
+
RFC 5892 IDNA Code Points August 2010
2301
+
2302
+
2303
+
1360..137C ; DISALLOWED # ETHIOPIC SECTION MARK..ETHIOPIC NUMBER TEN T
2304
+
137D..137F ; UNASSIGNED # <reserved>..<reserved>
2305
+
1380..138F ; PVALID # ETHIOPIC SYLLABLE SEBATBEIT MWA..ETHIOPIC SY
2306
+
1390..1399 ; DISALLOWED # ETHIOPIC TONAL MARK YIZET..ETHIOPIC TONAL MA
2307
+
139A..139F ; UNASSIGNED # <reserved>..<reserved>
2308
+
13A0..13F4 ; PVALID # CHEROKEE LETTER A..CHEROKEE LETTER YV
2309
+
13F5..13FF ; UNASSIGNED # <reserved>..<reserved>
2310
+
1400 ; DISALLOWED # CANADIAN SYLLABICS HYPHEN
2311
+
1401..166C ; PVALID # CANADIAN SYLLABICS E..CANADIAN SYLLABICS CAR
2312
+
166D..166E ; DISALLOWED # CANADIAN SYLLABICS CHI SIGN..CANADIAN SYLLAB
2313
+
166F..167F ; PVALID # CANADIAN SYLLABICS QAI..CANADIAN SYLLABICS B
2314
+
1680 ; DISALLOWED # OGHAM SPACE MARK
2315
+
1681..169A ; PVALID # OGHAM LETTER BEITH..OGHAM LETTER PEITH
2316
+
169B..169C ; DISALLOWED # OGHAM FEATHER MARK..OGHAM REVERSED FEATHER M
2317
+
169D..169F ; UNASSIGNED # <reserved>..<reserved>
2318
+
16A0..16EA ; PVALID # RUNIC LETTER FEHU FEOH FE F..RUNIC LETTER X
2319
+
16EB..16F0 ; DISALLOWED # RUNIC SINGLE PUNCTUATION..RUNIC BELGTHOR SYM
2320
+
16F1..16FF ; UNASSIGNED # <reserved>..<reserved>
2321
+
1700..170C ; PVALID # TAGALOG LETTER A..TAGALOG LETTER YA
2322
+
170D ; UNASSIGNED # <reserved>
2323
+
170E..1714 ; PVALID # TAGALOG LETTER LA..TAGALOG SIGN VIRAMA
2324
+
1715..171F ; UNASSIGNED # <reserved>..<reserved>
2325
+
1720..1734 ; PVALID # HANUNOO LETTER A..HANUNOO SIGN PAMUDPOD
2326
+
1735..1736 ; DISALLOWED # PHILIPPINE SINGLE PUNCTUATION..PHILIPPINE DO
2327
+
1737..173F ; UNASSIGNED # <reserved>..<reserved>
2328
+
1740..1753 ; PVALID # BUHID LETTER A..BUHID VOWEL SIGN U
2329
+
1754..175F ; UNASSIGNED # <reserved>..<reserved>
2330
+
1760..176C ; PVALID # TAGBANWA LETTER A..TAGBANWA LETTER YA
2331
+
176D ; UNASSIGNED # <reserved>
2332
+
176E..1770 ; PVALID # TAGBANWA LETTER LA..TAGBANWA LETTER SA
2333
+
1771 ; UNASSIGNED # <reserved>
2334
+
1772..1773 ; PVALID # TAGBANWA VOWEL SIGN I..TAGBANWA VOWEL SIGN U
2335
+
1774..177F ; UNASSIGNED # <reserved>..<reserved>
2336
+
1780..17B3 ; PVALID # KHMER LETTER KA..KHMER INDEPENDENT VOWEL QAU
2337
+
17B4..17B5 ; DISALLOWED # KHMER VOWEL INHERENT AQ..KHMER VOWEL INHEREN
2338
+
17B6..17D3 ; PVALID # KHMER VOWEL SIGN AA..KHMER SIGN BATHAMASAT
2339
+
17D4..17D6 ; DISALLOWED # KHMER SIGN KHAN..KHMER SIGN CAMNUC PII KUUH
2340
+
17D7 ; PVALID # KHMER SIGN LEK TOO
2341
+
17D8..17DB ; DISALLOWED # KHMER SIGN BEYYAL..KHMER CURRENCY SYMBOL RIE
2342
+
17DC..17DD ; PVALID # KHMER SIGN AVAKRAHASANYA..KHMER SIGN ATTHACA
2343
+
17DE..17DF ; UNASSIGNED # <reserved>..<reserved>
2344
+
17E0..17E9 ; PVALID # KHMER DIGIT ZERO..KHMER DIGIT NINE
2345
+
17EA..17EF ; UNASSIGNED # <reserved>..<reserved>
2346
+
17F0..17F9 ; DISALLOWED # KHMER SYMBOL LEK ATTAK SON..KHMER SYMBOL LEK
2347
+
17FA..17FF ; UNASSIGNED # <reserved>..<reserved>
2348
+
1800..180E ; DISALLOWED # MONGOLIAN BIRGA..MONGOLIAN VOWEL SEPARATOR
2349
+
180F ; UNASSIGNED # <reserved>
2350
+
1810..1819 ; PVALID # MONGOLIAN DIGIT ZERO..MONGOLIAN DIGIT NINE
2351
+
2352
+
2353
+
2354
+
Faltstrom Standards Track [Page 42]
2355
+
2356
+
RFC 5892 IDNA Code Points August 2010
2357
+
2358
+
2359
+
181A..181F ; UNASSIGNED # <reserved>..<reserved>
2360
+
1820..1877 ; PVALID # MONGOLIAN LETTER A..MONGOLIAN LETTER MANCHU
2361
+
1878..187F ; UNASSIGNED # <reserved>..<reserved>
2362
+
1880..18AA ; PVALID # MONGOLIAN LETTER ALI GALI ANUSVARA ONE..MONG
2363
+
18AB..18AF ; UNASSIGNED # <reserved>..<reserved>
2364
+
18B0..18F5 ; PVALID # CANADIAN SYLLABICS OY..CANADIAN SYLLABICS CA
2365
+
18F6..18FF ; UNASSIGNED # <reserved>..<reserved>
2366
+
1900..191C ; PVALID # LIMBU VOWEL-CARRIER LETTER..LIMBU LETTER HA
2367
+
191D..191F ; UNASSIGNED # <reserved>..<reserved>
2368
+
1920..192B ; PVALID # LIMBU VOWEL SIGN A..LIMBU SUBJOINED LETTER W
2369
+
192C..192F ; UNASSIGNED # <reserved>..<reserved>
2370
+
1930..193B ; PVALID # LIMBU SMALL LETTER KA..LIMBU SIGN SA-I
2371
+
193C..193F ; UNASSIGNED # <reserved>..<reserved>
2372
+
1940 ; DISALLOWED # LIMBU SIGN LOO
2373
+
1941..1943 ; UNASSIGNED # <reserved>..<reserved>
2374
+
1944..1945 ; DISALLOWED # LIMBU EXCLAMATION MARK..LIMBU QUESTION MARK
2375
+
1946..196D ; PVALID # LIMBU DIGIT ZERO..TAI LE LETTER AI
2376
+
196E..196F ; UNASSIGNED # <reserved>..<reserved>
2377
+
1970..1974 ; PVALID # TAI LE LETTER TONE-2..TAI LE LETTER TONE-6
2378
+
1975..197F ; UNASSIGNED # <reserved>..<reserved>
2379
+
1980..19AB ; PVALID # NEW TAI LUE LETTER HIGH QA..NEW TAI LUE LETT
2380
+
19AC..19AF ; UNASSIGNED # <reserved>..<reserved>
2381
+
19B0..19C9 ; PVALID # NEW TAI LUE VOWEL SIGN VOWEL SHORTENER..NEW
2382
+
19CA..19CF ; UNASSIGNED # <reserved>..<reserved>
2383
+
19D0..19DA ; PVALID # NEW TAI LUE DIGIT ZERO..NEW TAI LUE THAM DIG
2384
+
19DB..19DD ; UNASSIGNED # <reserved>..<reserved>
2385
+
19DE..19FF ; DISALLOWED # NEW TAI LUE SIGN LAE..KHMER SYMBOL DAP-PRAM
2386
+
1A00..1A1B ; PVALID # BUGINESE LETTER KA..BUGINESE VOWEL SIGN AE
2387
+
1A1C..1A1D ; UNASSIGNED # <reserved>..<reserved>
2388
+
1A1E..1A1F ; DISALLOWED # BUGINESE PALLAWA..BUGINESE END OF SECTION
2389
+
1A20..1A5E ; PVALID # TAI THAM LETTER HIGH KA..TAI THAM CONSONANT
2390
+
1A5F ; UNASSIGNED # <reserved>
2391
+
1A60..1A7C ; PVALID # TAI THAM SIGN SAKOT..TAI THAM SIGN KHUEN-LUE
2392
+
1A7D..1A7E ; UNASSIGNED # <reserved>..<reserved>
2393
+
1A7F..1A89 ; PVALID # TAI THAM COMBINING CRYPTOGRAMMIC DOT..TAI TH
2394
+
1A8A..1A8F ; UNASSIGNED # <reserved>..<reserved>
2395
+
1A90..1A99 ; PVALID # TAI THAM THAM DIGIT ZERO..TAI THAM THAM DIGI
2396
+
1A9A..1A9F ; UNASSIGNED # <reserved>..<reserved>
2397
+
1AA0..1AA6 ; DISALLOWED # TAI THAM SIGN WIANG..TAI THAM SIGN REVERSED
2398
+
1AA7 ; PVALID # TAI THAM SIGN MAI YAMOK
2399
+
1AA8..1AAD ; DISALLOWED # TAI THAM SIGN KAAN..TAI THAM SIGN CAANG
2400
+
1AAE..1AFF ; UNASSIGNED # <reserved>..<reserved>
2401
+
1B00..1B4B ; PVALID # BALINESE SIGN ULU RICEM..BALINESE LETTER ASY
2402
+
1B4C..1B4F ; UNASSIGNED # <reserved>..<reserved>
2403
+
1B50..1B59 ; PVALID # BALINESE DIGIT ZERO..BALINESE DIGIT NINE
2404
+
1B5A..1B6A ; DISALLOWED # BALINESE PANTI..BALINESE MUSICAL SYMBOL DANG
2405
+
1B6B..1B73 ; PVALID # BALINESE MUSICAL SYMBOL COMBINING TEGEH..BAL
2406
+
1B74..1B7C ; DISALLOWED # BALINESE MUSICAL SYMBOL RIGHT-HAND OPEN DUG.
2407
+
2408
+
2409
+
2410
+
Faltstrom Standards Track [Page 43]
2411
+
2412
+
RFC 5892 IDNA Code Points August 2010
2413
+
2414
+
2415
+
1B7D..1B7F ; UNASSIGNED # <reserved>..<reserved>
2416
+
1B80..1BAA ; PVALID # SUNDANESE SIGN PANYECEK..SUNDANESE SIGN PAMA
2417
+
1BAB..1BAD ; UNASSIGNED # <reserved>..<reserved>
2418
+
1BAE..1BB9 ; PVALID # SUNDANESE LETTER KHA..SUNDANESE DIGIT NINE
2419
+
1BBA..1BFF ; UNASSIGNED # <reserved>..<reserved>
2420
+
1C00..1C37 ; PVALID # LEPCHA LETTER KA..LEPCHA SIGN NUKTA
2421
+
1C38..1C3A ; UNASSIGNED # <reserved>..<reserved>
2422
+
1C3B..1C3F ; DISALLOWED # LEPCHA PUNCTUATION TA-ROL..LEPCHA PUNCTUATIO
2423
+
1C40..1C49 ; PVALID # LEPCHA DIGIT ZERO..LEPCHA DIGIT NINE
2424
+
1C4A..1C4C ; UNASSIGNED # <reserved>..<reserved>
2425
+
1C4D..1C7D ; PVALID # LEPCHA LETTER TTA..OL CHIKI AHAD
2426
+
1C7E..1C7F ; DISALLOWED # OL CHIKI PUNCTUATION MUCAAD..OL CHIKI PUNCTU
2427
+
1C80..1CCF ; UNASSIGNED # <reserved>..<reserved>
2428
+
1CD0..1CD2 ; PVALID # VEDIC TONE KARSHANA..VEDIC TONE PRENKHA
2429
+
1CD3 ; DISALLOWED # VEDIC SIGN NIHSHVASA
2430
+
1CD4..1CF2 ; PVALID # VEDIC SIGN YAJURVEDIC MIDLINE SVARITA..VEDIC
2431
+
1CF3..1CFF ; UNASSIGNED # <reserved>..<reserved>
2432
+
1D00..1D2B ; PVALID # LATIN LETTER SMALL CAPITAL A..CYRILLIC LETTE
2433
+
1D2C..1D2E ; DISALLOWED # MODIFIER LETTER CAPITAL A..MODIFIER LETTER C
2434
+
1D2F ; PVALID # MODIFIER LETTER CAPITAL BARRED B
2435
+
1D30..1D3A ; DISALLOWED # MODIFIER LETTER CAPITAL D..MODIFIER LETTER C
2436
+
1D3B ; PVALID # MODIFIER LETTER CAPITAL REVERSED N
2437
+
1D3C..1D4D ; DISALLOWED # MODIFIER LETTER CAPITAL O..MODIFIER LETTER S
2438
+
1D4E ; PVALID # MODIFIER LETTER SMALL TURNED I
2439
+
1D4F..1D6A ; DISALLOWED # MODIFIER LETTER SMALL K..GREEK SUBSCRIPT SMA
2440
+
1D6B..1D77 ; PVALID # LATIN SMALL LETTER UE..LATIN SMALL LETTER TU
2441
+
1D78 ; DISALLOWED # MODIFIER LETTER CYRILLIC EN
2442
+
1D79..1D9A ; PVALID # LATIN SMALL LETTER INSULAR G..LATIN SMALL LE
2443
+
1D9B..1DBF ; DISALLOWED # MODIFIER LETTER SMALL TURNED ALPHA..MODIFIER
2444
+
1DC0..1DE6 ; PVALID # COMBINING DOTTED GRAVE ACCENT..COMBINING LAT
2445
+
1DE7..1DFC ; UNASSIGNED # <reserved>..<reserved>
2446
+
1DFD..1DFF ; PVALID # COMBINING ALMOST EQUAL TO BELOW..COMBINING R
2447
+
1E00 ; DISALLOWED # LATIN CAPITAL LETTER A WITH RING BELOW
2448
+
1E01 ; PVALID # LATIN SMALL LETTER A WITH RING BELOW
2449
+
1E02 ; DISALLOWED # LATIN CAPITAL LETTER B WITH DOT ABOVE
2450
+
1E03 ; PVALID # LATIN SMALL LETTER B WITH DOT ABOVE
2451
+
1E04 ; DISALLOWED # LATIN CAPITAL LETTER B WITH DOT BELOW
2452
+
1E05 ; PVALID # LATIN SMALL LETTER B WITH DOT BELOW
2453
+
1E06 ; DISALLOWED # LATIN CAPITAL LETTER B WITH LINE BELOW
2454
+
1E07 ; PVALID # LATIN SMALL LETTER B WITH LINE BELOW
2455
+
1E08 ; DISALLOWED # LATIN CAPITAL LETTER C WITH CEDILLA AND ACUT
2456
+
1E09 ; PVALID # LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
2457
+
1E0A ; DISALLOWED # LATIN CAPITAL LETTER D WITH DOT ABOVE
2458
+
1E0B ; PVALID # LATIN SMALL LETTER D WITH DOT ABOVE
2459
+
1E0C ; DISALLOWED # LATIN CAPITAL LETTER D WITH DOT BELOW
2460
+
1E0D ; PVALID # LATIN SMALL LETTER D WITH DOT BELOW
2461
+
1E0E ; DISALLOWED # LATIN CAPITAL LETTER D WITH LINE BELOW
2462
+
1E0F ; PVALID # LATIN SMALL LETTER D WITH LINE BELOW
2463
+
2464
+
2465
+
2466
+
Faltstrom Standards Track [Page 44]
2467
+
2468
+
RFC 5892 IDNA Code Points August 2010
2469
+
2470
+
2471
+
1E10 ; DISALLOWED # LATIN CAPITAL LETTER D WITH CEDILLA
2472
+
1E11 ; PVALID # LATIN SMALL LETTER D WITH CEDILLA
2473
+
1E12 ; DISALLOWED # LATIN CAPITAL LETTER D WITH CIRCUMFLEX BELOW
2474
+
1E13 ; PVALID # LATIN SMALL LETTER D WITH CIRCUMFLEX BELOW
2475
+
1E14 ; DISALLOWED # LATIN CAPITAL LETTER E WITH MACRON AND GRAVE
2476
+
1E15 ; PVALID # LATIN SMALL LETTER E WITH MACRON AND GRAVE
2477
+
1E16 ; DISALLOWED # LATIN CAPITAL LETTER E WITH MACRON AND ACUTE
2478
+
1E17 ; PVALID # LATIN SMALL LETTER E WITH MACRON AND ACUTE
2479
+
1E18 ; DISALLOWED # LATIN CAPITAL LETTER E WITH CIRCUMFLEX BELOW
2480
+
1E19 ; PVALID # LATIN SMALL LETTER E WITH CIRCUMFLEX BELOW
2481
+
1E1A ; DISALLOWED # LATIN CAPITAL LETTER E WITH TILDE BELOW
2482
+
1E1B ; PVALID # LATIN SMALL LETTER E WITH TILDE BELOW
2483
+
1E1C ; DISALLOWED # LATIN CAPITAL LETTER E WITH CEDILLA AND BREV
2484
+
1E1D ; PVALID # LATIN SMALL LETTER E WITH CEDILLA AND BREVE
2485
+
1E1E ; DISALLOWED # LATIN CAPITAL LETTER F WITH DOT ABOVE
2486
+
1E1F ; PVALID # LATIN SMALL LETTER F WITH DOT ABOVE
2487
+
1E20 ; DISALLOWED # LATIN CAPITAL LETTER G WITH MACRON
2488
+
1E21 ; PVALID # LATIN SMALL LETTER G WITH MACRON
2489
+
1E22 ; DISALLOWED # LATIN CAPITAL LETTER H WITH DOT ABOVE
2490
+
1E23 ; PVALID # LATIN SMALL LETTER H WITH DOT ABOVE
2491
+
1E24 ; DISALLOWED # LATIN CAPITAL LETTER H WITH DOT BELOW
2492
+
1E25 ; PVALID # LATIN SMALL LETTER H WITH DOT BELOW
2493
+
1E26 ; DISALLOWED # LATIN CAPITAL LETTER H WITH DIAERESIS
2494
+
1E27 ; PVALID # LATIN SMALL LETTER H WITH DIAERESIS
2495
+
1E28 ; DISALLOWED # LATIN CAPITAL LETTER H WITH CEDILLA
2496
+
1E29 ; PVALID # LATIN SMALL LETTER H WITH CEDILLA
2497
+
1E2A ; DISALLOWED # LATIN CAPITAL LETTER H WITH BREVE BELOW
2498
+
1E2B ; PVALID # LATIN SMALL LETTER H WITH BREVE BELOW
2499
+
1E2C ; DISALLOWED # LATIN CAPITAL LETTER I WITH TILDE BELOW
2500
+
1E2D ; PVALID # LATIN SMALL LETTER I WITH TILDE BELOW
2501
+
1E2E ; DISALLOWED # LATIN CAPITAL LETTER I WITH DIAERESIS AND AC
2502
+
1E2F ; PVALID # LATIN SMALL LETTER I WITH DIAERESIS AND ACUT
2503
+
1E30 ; DISALLOWED # LATIN CAPITAL LETTER K WITH ACUTE
2504
+
1E31 ; PVALID # LATIN SMALL LETTER K WITH ACUTE
2505
+
1E32 ; DISALLOWED # LATIN CAPITAL LETTER K WITH DOT BELOW
2506
+
1E33 ; PVALID # LATIN SMALL LETTER K WITH DOT BELOW
2507
+
1E34 ; DISALLOWED # LATIN CAPITAL LETTER K WITH LINE BELOW
2508
+
1E35 ; PVALID # LATIN SMALL LETTER K WITH LINE BELOW
2509
+
1E36 ; DISALLOWED # LATIN CAPITAL LETTER L WITH DOT BELOW
2510
+
1E37 ; PVALID # LATIN SMALL LETTER L WITH DOT BELOW
2511
+
1E38 ; DISALLOWED # LATIN CAPITAL LETTER L WITH DOT BELOW AND MA
2512
+
1E39 ; PVALID # LATIN SMALL LETTER L WITH DOT BELOW AND MACR
2513
+
1E3A ; DISALLOWED # LATIN CAPITAL LETTER L WITH LINE BELOW
2514
+
1E3B ; PVALID # LATIN SMALL LETTER L WITH LINE BELOW
2515
+
1E3C ; DISALLOWED # LATIN CAPITAL LETTER L WITH CIRCUMFLEX BELOW
2516
+
1E3D ; PVALID # LATIN SMALL LETTER L WITH CIRCUMFLEX BELOW
2517
+
1E3E ; DISALLOWED # LATIN CAPITAL LETTER M WITH ACUTE
2518
+
1E3F ; PVALID # LATIN SMALL LETTER M WITH ACUTE
2519
+
2520
+
2521
+
2522
+
Faltstrom Standards Track [Page 45]
2523
+
2524
+
RFC 5892 IDNA Code Points August 2010
2525
+
2526
+
2527
+
1E40 ; DISALLOWED # LATIN CAPITAL LETTER M WITH DOT ABOVE
2528
+
1E41 ; PVALID # LATIN SMALL LETTER M WITH DOT ABOVE
2529
+
1E42 ; DISALLOWED # LATIN CAPITAL LETTER M WITH DOT BELOW
2530
+
1E43 ; PVALID # LATIN SMALL LETTER M WITH DOT BELOW
2531
+
1E44 ; DISALLOWED # LATIN CAPITAL LETTER N WITH DOT ABOVE
2532
+
1E45 ; PVALID # LATIN SMALL LETTER N WITH DOT ABOVE
2533
+
1E46 ; DISALLOWED # LATIN CAPITAL LETTER N WITH DOT BELOW
2534
+
1E47 ; PVALID # LATIN SMALL LETTER N WITH DOT BELOW
2535
+
1E48 ; DISALLOWED # LATIN CAPITAL LETTER N WITH LINE BELOW
2536
+
1E49 ; PVALID # LATIN SMALL LETTER N WITH LINE BELOW
2537
+
1E4A ; DISALLOWED # LATIN CAPITAL LETTER N WITH CIRCUMFLEX BELOW
2538
+
1E4B ; PVALID # LATIN SMALL LETTER N WITH CIRCUMFLEX BELOW
2539
+
1E4C ; DISALLOWED # LATIN CAPITAL LETTER O WITH TILDE AND ACUTE
2540
+
1E4D ; PVALID # LATIN SMALL LETTER O WITH TILDE AND ACUTE
2541
+
1E4E ; DISALLOWED # LATIN CAPITAL LETTER O WITH TILDE AND DIAERE
2542
+
1E4F ; PVALID # LATIN SMALL LETTER O WITH TILDE AND DIAERESI
2543
+
1E50 ; DISALLOWED # LATIN CAPITAL LETTER O WITH MACRON AND GRAVE
2544
+
1E51 ; PVALID # LATIN SMALL LETTER O WITH MACRON AND GRAVE
2545
+
1E52 ; DISALLOWED # LATIN CAPITAL LETTER O WITH MACRON AND ACUTE
2546
+
1E53 ; PVALID # LATIN SMALL LETTER O WITH MACRON AND ACUTE
2547
+
1E54 ; DISALLOWED # LATIN CAPITAL LETTER P WITH ACUTE
2548
+
1E55 ; PVALID # LATIN SMALL LETTER P WITH ACUTE
2549
+
1E56 ; DISALLOWED # LATIN CAPITAL LETTER P WITH DOT ABOVE
2550
+
1E57 ; PVALID # LATIN SMALL LETTER P WITH DOT ABOVE
2551
+
1E58 ; DISALLOWED # LATIN CAPITAL LETTER R WITH DOT ABOVE
2552
+
1E59 ; PVALID # LATIN SMALL LETTER R WITH DOT ABOVE
2553
+
1E5A ; DISALLOWED # LATIN CAPITAL LETTER R WITH DOT BELOW
2554
+
1E5B ; PVALID # LATIN SMALL LETTER R WITH DOT BELOW
2555
+
1E5C ; DISALLOWED # LATIN CAPITAL LETTER R WITH DOT BELOW AND MA
2556
+
1E5D ; PVALID # LATIN SMALL LETTER R WITH DOT BELOW AND MACR
2557
+
1E5E ; DISALLOWED # LATIN CAPITAL LETTER R WITH LINE BELOW
2558
+
1E5F ; PVALID # LATIN SMALL LETTER R WITH LINE BELOW
2559
+
1E60 ; DISALLOWED # LATIN CAPITAL LETTER S WITH DOT ABOVE
2560
+
1E61 ; PVALID # LATIN SMALL LETTER S WITH DOT ABOVE
2561
+
1E62 ; DISALLOWED # LATIN CAPITAL LETTER S WITH DOT BELOW
2562
+
1E63 ; PVALID # LATIN SMALL LETTER S WITH DOT BELOW
2563
+
1E64 ; DISALLOWED # LATIN CAPITAL LETTER S WITH ACUTE AND DOT AB
2564
+
1E65 ; PVALID # LATIN SMALL LETTER S WITH ACUTE AND DOT ABOV
2565
+
1E66 ; DISALLOWED # LATIN CAPITAL LETTER S WITH CARON AND DOT AB
2566
+
1E67 ; PVALID # LATIN SMALL LETTER S WITH CARON AND DOT ABOV
2567
+
1E68 ; DISALLOWED # LATIN CAPITAL LETTER S WITH DOT BELOW AND DO
2568
+
1E69 ; PVALID # LATIN SMALL LETTER S WITH DOT BELOW AND DOT
2569
+
1E6A ; DISALLOWED # LATIN CAPITAL LETTER T WITH DOT ABOVE
2570
+
1E6B ; PVALID # LATIN SMALL LETTER T WITH DOT ABOVE
2571
+
1E6C ; DISALLOWED # LATIN CAPITAL LETTER T WITH DOT BELOW
2572
+
1E6D ; PVALID # LATIN SMALL LETTER T WITH DOT BELOW
2573
+
1E6E ; DISALLOWED # LATIN CAPITAL LETTER T WITH LINE BELOW
2574
+
1E6F ; PVALID # LATIN SMALL LETTER T WITH LINE BELOW
2575
+
2576
+
2577
+
2578
+
Faltstrom Standards Track [Page 46]
2579
+
2580
+
RFC 5892 IDNA Code Points August 2010
2581
+
2582
+
2583
+
1E70 ; DISALLOWED # LATIN CAPITAL LETTER T WITH CIRCUMFLEX BELOW
2584
+
1E71 ; PVALID # LATIN SMALL LETTER T WITH CIRCUMFLEX BELOW
2585
+
1E72 ; DISALLOWED # LATIN CAPITAL LETTER U WITH DIAERESIS BELOW
2586
+
1E73 ; PVALID # LATIN SMALL LETTER U WITH DIAERESIS BELOW
2587
+
1E74 ; DISALLOWED # LATIN CAPITAL LETTER U WITH TILDE BELOW
2588
+
1E75 ; PVALID # LATIN SMALL LETTER U WITH TILDE BELOW
2589
+
1E76 ; DISALLOWED # LATIN CAPITAL LETTER U WITH CIRCUMFLEX BELOW
2590
+
1E77 ; PVALID # LATIN SMALL LETTER U WITH CIRCUMFLEX BELOW
2591
+
1E78 ; DISALLOWED # LATIN CAPITAL LETTER U WITH TILDE AND ACUTE
2592
+
1E79 ; PVALID # LATIN SMALL LETTER U WITH TILDE AND ACUTE
2593
+
1E7A ; DISALLOWED # LATIN CAPITAL LETTER U WITH MACRON AND DIAER
2594
+
1E7B ; PVALID # LATIN SMALL LETTER U WITH MACRON AND DIAERES
2595
+
1E7C ; DISALLOWED # LATIN CAPITAL LETTER V WITH TILDE
2596
+
1E7D ; PVALID # LATIN SMALL LETTER V WITH TILDE
2597
+
1E7E ; DISALLOWED # LATIN CAPITAL LETTER V WITH DOT BELOW
2598
+
1E7F ; PVALID # LATIN SMALL LETTER V WITH DOT BELOW
2599
+
1E80 ; DISALLOWED # LATIN CAPITAL LETTER W WITH GRAVE
2600
+
1E81 ; PVALID # LATIN SMALL LETTER W WITH GRAVE
2601
+
1E82 ; DISALLOWED # LATIN CAPITAL LETTER W WITH ACUTE
2602
+
1E83 ; PVALID # LATIN SMALL LETTER W WITH ACUTE
2603
+
1E84 ; DISALLOWED # LATIN CAPITAL LETTER W WITH DIAERESIS
2604
+
1E85 ; PVALID # LATIN SMALL LETTER W WITH DIAERESIS
2605
+
1E86 ; DISALLOWED # LATIN CAPITAL LETTER W WITH DOT ABOVE
2606
+
1E87 ; PVALID # LATIN SMALL LETTER W WITH DOT ABOVE
2607
+
1E88 ; DISALLOWED # LATIN CAPITAL LETTER W WITH DOT BELOW
2608
+
1E89 ; PVALID # LATIN SMALL LETTER W WITH DOT BELOW
2609
+
1E8A ; DISALLOWED # LATIN CAPITAL LETTER X WITH DOT ABOVE
2610
+
1E8B ; PVALID # LATIN SMALL LETTER X WITH DOT ABOVE
2611
+
1E8C ; DISALLOWED # LATIN CAPITAL LETTER X WITH DIAERESIS
2612
+
1E8D ; PVALID # LATIN SMALL LETTER X WITH DIAERESIS
2613
+
1E8E ; DISALLOWED # LATIN CAPITAL LETTER Y WITH DOT ABOVE
2614
+
1E8F ; PVALID # LATIN SMALL LETTER Y WITH DOT ABOVE
2615
+
1E90 ; DISALLOWED # LATIN CAPITAL LETTER Z WITH CIRCUMFLEX
2616
+
1E91 ; PVALID # LATIN SMALL LETTER Z WITH CIRCUMFLEX
2617
+
1E92 ; DISALLOWED # LATIN CAPITAL LETTER Z WITH DOT BELOW
2618
+
1E93 ; PVALID # LATIN SMALL LETTER Z WITH DOT BELOW
2619
+
1E94 ; DISALLOWED # LATIN CAPITAL LETTER Z WITH LINE BELOW
2620
+
1E95..1E99 ; PVALID # LATIN SMALL LETTER Z WITH LINE BELOW..LATIN
2621
+
1E9A..1E9B ; DISALLOWED # LATIN SMALL LETTER A WITH RIGHT HALF RING..L
2622
+
1E9C..1E9D ; PVALID # LATIN SMALL LETTER LONG S WITH DIAGONAL STRO
2623
+
1E9E ; DISALLOWED # LATIN CAPITAL LETTER SHARP S
2624
+
1E9F ; PVALID # LATIN SMALL LETTER DELTA
2625
+
1EA0 ; DISALLOWED # LATIN CAPITAL LETTER A WITH DOT BELOW
2626
+
1EA1 ; PVALID # LATIN SMALL LETTER A WITH DOT BELOW
2627
+
1EA2 ; DISALLOWED # LATIN CAPITAL LETTER A WITH HOOK ABOVE
2628
+
1EA3 ; PVALID # LATIN SMALL LETTER A WITH HOOK ABOVE
2629
+
1EA4 ; DISALLOWED # LATIN CAPITAL LETTER A WITH CIRCUMFLEX AND A
2630
+
1EA5 ; PVALID # LATIN SMALL LETTER A WITH CIRCUMFLEX AND ACU
2631
+
2632
+
2633
+
2634
+
Faltstrom Standards Track [Page 47]
2635
+
2636
+
RFC 5892 IDNA Code Points August 2010
2637
+
2638
+
2639
+
1EA6 ; DISALLOWED # LATIN CAPITAL LETTER A WITH CIRCUMFLEX AND G
2640
+
1EA7 ; PVALID # LATIN SMALL LETTER A WITH CIRCUMFLEX AND GRA
2641
+
1EA8 ; DISALLOWED # LATIN CAPITAL LETTER A WITH CIRCUMFLEX AND H
2642
+
1EA9 ; PVALID # LATIN SMALL LETTER A WITH CIRCUMFLEX AND HOO
2643
+
1EAA ; DISALLOWED # LATIN CAPITAL LETTER A WITH CIRCUMFLEX AND T
2644
+
1EAB ; PVALID # LATIN SMALL LETTER A WITH CIRCUMFLEX AND TIL
2645
+
1EAC ; DISALLOWED # LATIN CAPITAL LETTER A WITH CIRCUMFLEX AND D
2646
+
1EAD ; PVALID # LATIN SMALL LETTER A WITH CIRCUMFLEX AND DOT
2647
+
1EAE ; DISALLOWED # LATIN CAPITAL LETTER A WITH BREVE AND ACUTE
2648
+
1EAF ; PVALID # LATIN SMALL LETTER A WITH BREVE AND ACUTE
2649
+
1EB0 ; DISALLOWED # LATIN CAPITAL LETTER A WITH BREVE AND GRAVE
2650
+
1EB1 ; PVALID # LATIN SMALL LETTER A WITH BREVE AND GRAVE
2651
+
1EB2 ; DISALLOWED # LATIN CAPITAL LETTER A WITH BREVE AND HOOK A
2652
+
1EB3 ; PVALID # LATIN SMALL LETTER A WITH BREVE AND HOOK ABO
2653
+
1EB4 ; DISALLOWED # LATIN CAPITAL LETTER A WITH BREVE AND TILDE
2654
+
1EB5 ; PVALID # LATIN SMALL LETTER A WITH BREVE AND TILDE
2655
+
1EB6 ; DISALLOWED # LATIN CAPITAL LETTER A WITH BREVE AND DOT BE
2656
+
1EB7 ; PVALID # LATIN SMALL LETTER A WITH BREVE AND DOT BELO
2657
+
1EB8 ; DISALLOWED # LATIN CAPITAL LETTER E WITH DOT BELOW
2658
+
1EB9 ; PVALID # LATIN SMALL LETTER E WITH DOT BELOW
2659
+
1EBA ; DISALLOWED # LATIN CAPITAL LETTER E WITH HOOK ABOVE
2660
+
1EBB ; PVALID # LATIN SMALL LETTER E WITH HOOK ABOVE
2661
+
1EBC ; DISALLOWED # LATIN CAPITAL LETTER E WITH TILDE
2662
+
1EBD ; PVALID # LATIN SMALL LETTER E WITH TILDE
2663
+
1EBE ; DISALLOWED # LATIN CAPITAL LETTER E WITH CIRCUMFLEX AND A
2664
+
1EBF ; PVALID # LATIN SMALL LETTER E WITH CIRCUMFLEX AND ACU
2665
+
1EC0 ; DISALLOWED # LATIN CAPITAL LETTER E WITH CIRCUMFLEX AND G
2666
+
1EC1 ; PVALID # LATIN SMALL LETTER E WITH CIRCUMFLEX AND GRA
2667
+
1EC2 ; DISALLOWED # LATIN CAPITAL LETTER E WITH CIRCUMFLEX AND H
2668
+
1EC3 ; PVALID # LATIN SMALL LETTER E WITH CIRCUMFLEX AND HOO
2669
+
1EC4 ; DISALLOWED # LATIN CAPITAL LETTER E WITH CIRCUMFLEX AND T
2670
+
1EC5 ; PVALID # LATIN SMALL LETTER E WITH CIRCUMFLEX AND TIL
2671
+
1EC6 ; DISALLOWED # LATIN CAPITAL LETTER E WITH CIRCUMFLEX AND D
2672
+
1EC7 ; PVALID # LATIN SMALL LETTER E WITH CIRCUMFLEX AND DOT
2673
+
1EC8 ; DISALLOWED # LATIN CAPITAL LETTER I WITH HOOK ABOVE
2674
+
1EC9 ; PVALID # LATIN SMALL LETTER I WITH HOOK ABOVE
2675
+
1ECA ; DISALLOWED # LATIN CAPITAL LETTER I WITH DOT BELOW
2676
+
1ECB ; PVALID # LATIN SMALL LETTER I WITH DOT BELOW
2677
+
1ECC ; DISALLOWED # LATIN CAPITAL LETTER O WITH DOT BELOW
2678
+
1ECD ; PVALID # LATIN SMALL LETTER O WITH DOT BELOW
2679
+
1ECE ; DISALLOWED # LATIN CAPITAL LETTER O WITH HOOK ABOVE
2680
+
1ECF ; PVALID # LATIN SMALL LETTER O WITH HOOK ABOVE
2681
+
1ED0 ; DISALLOWED # LATIN CAPITAL LETTER O WITH CIRCUMFLEX AND A
2682
+
1ED1 ; PVALID # LATIN SMALL LETTER O WITH CIRCUMFLEX AND ACU
2683
+
1ED2 ; DISALLOWED # LATIN CAPITAL LETTER O WITH CIRCUMFLEX AND G
2684
+
1ED3 ; PVALID # LATIN SMALL LETTER O WITH CIRCUMFLEX AND GRA
2685
+
1ED4 ; DISALLOWED # LATIN CAPITAL LETTER O WITH CIRCUMFLEX AND H
2686
+
1ED5 ; PVALID # LATIN SMALL LETTER O WITH CIRCUMFLEX AND HOO
2687
+
2688
+
2689
+
2690
+
Faltstrom Standards Track [Page 48]
2691
+
2692
+
RFC 5892 IDNA Code Points August 2010
2693
+
2694
+
2695
+
1ED6 ; DISALLOWED # LATIN CAPITAL LETTER O WITH CIRCUMFLEX AND T
2696
+
1ED7 ; PVALID # LATIN SMALL LETTER O WITH CIRCUMFLEX AND TIL
2697
+
1ED8 ; DISALLOWED # LATIN CAPITAL LETTER O WITH CIRCUMFLEX AND D
2698
+
1ED9 ; PVALID # LATIN SMALL LETTER O WITH CIRCUMFLEX AND DOT
2699
+
1EDA ; DISALLOWED # LATIN CAPITAL LETTER O WITH HORN AND ACUTE
2700
+
1EDB ; PVALID # LATIN SMALL LETTER O WITH HORN AND ACUTE
2701
+
1EDC ; DISALLOWED # LATIN CAPITAL LETTER O WITH HORN AND GRAVE
2702
+
1EDD ; PVALID # LATIN SMALL LETTER O WITH HORN AND GRAVE
2703
+
1EDE ; DISALLOWED # LATIN CAPITAL LETTER O WITH HORN AND HOOK AB
2704
+
1EDF ; PVALID # LATIN SMALL LETTER O WITH HORN AND HOOK ABOV
2705
+
1EE0 ; DISALLOWED # LATIN CAPITAL LETTER O WITH HORN AND TILDE
2706
+
1EE1 ; PVALID # LATIN SMALL LETTER O WITH HORN AND TILDE
2707
+
1EE2 ; DISALLOWED # LATIN CAPITAL LETTER O WITH HORN AND DOT BEL
2708
+
1EE3 ; PVALID # LATIN SMALL LETTER O WITH HORN AND DOT BELOW
2709
+
1EE4 ; DISALLOWED # LATIN CAPITAL LETTER U WITH DOT BELOW
2710
+
1EE5 ; PVALID # LATIN SMALL LETTER U WITH DOT BELOW
2711
+
1EE6 ; DISALLOWED # LATIN CAPITAL LETTER U WITH HOOK ABOVE
2712
+
1EE7 ; PVALID # LATIN SMALL LETTER U WITH HOOK ABOVE
2713
+
1EE8 ; DISALLOWED # LATIN CAPITAL LETTER U WITH HORN AND ACUTE
2714
+
1EE9 ; PVALID # LATIN SMALL LETTER U WITH HORN AND ACUTE
2715
+
1EEA ; DISALLOWED # LATIN CAPITAL LETTER U WITH HORN AND GRAVE
2716
+
1EEB ; PVALID # LATIN SMALL LETTER U WITH HORN AND GRAVE
2717
+
1EEC ; DISALLOWED # LATIN CAPITAL LETTER U WITH HORN AND HOOK AB
2718
+
1EED ; PVALID # LATIN SMALL LETTER U WITH HORN AND HOOK ABOV
2719
+
1EEE ; DISALLOWED # LATIN CAPITAL LETTER U WITH HORN AND TILDE
2720
+
1EEF ; PVALID # LATIN SMALL LETTER U WITH HORN AND TILDE
2721
+
1EF0 ; DISALLOWED # LATIN CAPITAL LETTER U WITH HORN AND DOT BEL
2722
+
1EF1 ; PVALID # LATIN SMALL LETTER U WITH HORN AND DOT BELOW
2723
+
1EF2 ; DISALLOWED # LATIN CAPITAL LETTER Y WITH GRAVE
2724
+
1EF3 ; PVALID # LATIN SMALL LETTER Y WITH GRAVE
2725
+
1EF4 ; DISALLOWED # LATIN CAPITAL LETTER Y WITH DOT BELOW
2726
+
1EF5 ; PVALID # LATIN SMALL LETTER Y WITH DOT BELOW
2727
+
1EF6 ; DISALLOWED # LATIN CAPITAL LETTER Y WITH HOOK ABOVE
2728
+
1EF7 ; PVALID # LATIN SMALL LETTER Y WITH HOOK ABOVE
2729
+
1EF8 ; DISALLOWED # LATIN CAPITAL LETTER Y WITH TILDE
2730
+
1EF9 ; PVALID # LATIN SMALL LETTER Y WITH TILDE
2731
+
1EFA ; DISALLOWED # LATIN CAPITAL LETTER MIDDLE-WELSH LL
2732
+
1EFB ; PVALID # LATIN SMALL LETTER MIDDLE-WELSH LL
2733
+
1EFC ; DISALLOWED # LATIN CAPITAL LETTER MIDDLE-WELSH V
2734
+
1EFD ; PVALID # LATIN SMALL LETTER MIDDLE-WELSH V
2735
+
1EFE ; DISALLOWED # LATIN CAPITAL LETTER Y WITH LOOP
2736
+
1EFF..1F07 ; PVALID # LATIN SMALL LETTER Y WITH LOOP..GREEK SMALL
2737
+
1F08..1F0F ; DISALLOWED # GREEK CAPITAL LETTER ALPHA WITH PSILI..GREEK
2738
+
1F10..1F15 ; PVALID # GREEK SMALL LETTER EPSILON WITH PSILI..GREEK
2739
+
1F16..1F17 ; UNASSIGNED # <reserved>..<reserved>
2740
+
1F18..1F1D ; DISALLOWED # GREEK CAPITAL LETTER EPSILON WITH PSILI..GRE
2741
+
1F1E..1F1F ; UNASSIGNED # <reserved>..<reserved>
2742
+
1F20..1F27 ; PVALID # GREEK SMALL LETTER ETA WITH PSILI..GREEK SMA
2743
+
2744
+
2745
+
2746
+
Faltstrom Standards Track [Page 49]
2747
+
2748
+
RFC 5892 IDNA Code Points August 2010
2749
+
2750
+
2751
+
1F28..1F2F ; DISALLOWED # GREEK CAPITAL LETTER ETA WITH PSILI..GREEK C
2752
+
1F30..1F37 ; PVALID # GREEK SMALL LETTER IOTA WITH PSILI..GREEK SM
2753
+
1F38..1F3F ; DISALLOWED # GREEK CAPITAL LETTER IOTA WITH PSILI..GREEK
2754
+
1F40..1F45 ; PVALID # GREEK SMALL LETTER OMICRON WITH PSILI..GREEK
2755
+
1F46..1F47 ; UNASSIGNED # <reserved>..<reserved>
2756
+
1F48..1F4D ; DISALLOWED # GREEK CAPITAL LETTER OMICRON WITH PSILI..GRE
2757
+
1F4E..1F4F ; UNASSIGNED # <reserved>..<reserved>
2758
+
1F50..1F57 ; PVALID # GREEK SMALL LETTER UPSILON WITH PSILI..GREEK
2759
+
1F58 ; UNASSIGNED # <reserved>
2760
+
1F59 ; DISALLOWED # GREEK CAPITAL LETTER UPSILON WITH DASIA
2761
+
1F5A ; UNASSIGNED # <reserved>
2762
+
1F5B ; DISALLOWED # GREEK CAPITAL LETTER UPSILON WITH DASIA AND
2763
+
1F5C ; UNASSIGNED # <reserved>
2764
+
1F5D ; DISALLOWED # GREEK CAPITAL LETTER UPSILON WITH DASIA AND
2765
+
1F5E ; UNASSIGNED # <reserved>
2766
+
1F5F ; DISALLOWED # GREEK CAPITAL LETTER UPSILON WITH DASIA AND
2767
+
1F60..1F67 ; PVALID # GREEK SMALL LETTER OMEGA WITH PSILI..GREEK S
2768
+
1F68..1F6F ; DISALLOWED # GREEK CAPITAL LETTER OMEGA WITH PSILI..GREEK
2769
+
1F70 ; PVALID # GREEK SMALL LETTER ALPHA WITH VARIA
2770
+
1F71 ; DISALLOWED # GREEK SMALL LETTER ALPHA WITH OXIA
2771
+
1F72 ; PVALID # GREEK SMALL LETTER EPSILON WITH VARIA
2772
+
1F73 ; DISALLOWED # GREEK SMALL LETTER EPSILON WITH OXIA
2773
+
1F74 ; PVALID # GREEK SMALL LETTER ETA WITH VARIA
2774
+
1F75 ; DISALLOWED # GREEK SMALL LETTER ETA WITH OXIA
2775
+
1F76 ; PVALID # GREEK SMALL LETTER IOTA WITH VARIA
2776
+
1F77 ; DISALLOWED # GREEK SMALL LETTER IOTA WITH OXIA
2777
+
1F78 ; PVALID # GREEK SMALL LETTER OMICRON WITH VARIA
2778
+
1F79 ; DISALLOWED # GREEK SMALL LETTER OMICRON WITH OXIA
2779
+
1F7A ; PVALID # GREEK SMALL LETTER UPSILON WITH VARIA
2780
+
1F7B ; DISALLOWED # GREEK SMALL LETTER UPSILON WITH OXIA
2781
+
1F7C ; PVALID # GREEK SMALL LETTER OMEGA WITH VARIA
2782
+
1F7D ; DISALLOWED # GREEK SMALL LETTER OMEGA WITH OXIA
2783
+
1F7E..1F7F ; UNASSIGNED # <reserved>..<reserved>
2784
+
1F80..1FAF ; DISALLOWED # GREEK SMALL LETTER ALPHA WITH PSILI AND YPOG
2785
+
1FB0..1FB1 ; PVALID # GREEK SMALL LETTER ALPHA WITH VRACHY..GREEK
2786
+
1FB2..1FB4 ; DISALLOWED # GREEK SMALL LETTER ALPHA WITH VARIA AND YPOG
2787
+
1FB5 ; UNASSIGNED # <reserved>
2788
+
1FB6 ; PVALID # GREEK SMALL LETTER ALPHA WITH PERISPOMENI
2789
+
1FB7..1FC4 ; DISALLOWED # GREEK SMALL LETTER ALPHA WITH PERISPOMENI AN
2790
+
1FC5 ; UNASSIGNED # <reserved>
2791
+
1FC6 ; PVALID # GREEK SMALL LETTER ETA WITH PERISPOMENI
2792
+
1FC7..1FCF ; DISALLOWED # GREEK SMALL LETTER ETA WITH PERISPOMENI AND
2793
+
1FD0..1FD2 ; PVALID # GREEK SMALL LETTER IOTA WITH VRACHY..GREEK S
2794
+
1FD3 ; DISALLOWED # GREEK SMALL LETTER IOTA WITH DIALYTIKA AND O
2795
+
1FD4..1FD5 ; UNASSIGNED # <reserved>..<reserved>
2796
+
1FD6..1FD7 ; PVALID # GREEK SMALL LETTER IOTA WITH PERISPOMENI..GR
2797
+
1FD8..1FDB ; DISALLOWED # GREEK CAPITAL LETTER IOTA WITH VRACHY..GREEK
2798
+
1FDC ; UNASSIGNED # <reserved>
2799
+
2800
+
2801
+
2802
+
Faltstrom Standards Track [Page 50]
2803
+
2804
+
RFC 5892 IDNA Code Points August 2010
2805
+
2806
+
2807
+
1FDD..1FDF ; DISALLOWED # GREEK DASIA AND VARIA..GREEK DASIA AND PERIS
2808
+
1FE0..1FE2 ; PVALID # GREEK SMALL LETTER UPSILON WITH VRACHY..GREE
2809
+
1FE3 ; DISALLOWED # GREEK SMALL LETTER UPSILON WITH DIALYTIKA AN
2810
+
1FE4..1FE7 ; PVALID # GREEK SMALL LETTER RHO WITH PSILI..GREEK SMA
2811
+
1FE8..1FEF ; DISALLOWED # GREEK CAPITAL LETTER UPSILON WITH VRACHY..GR
2812
+
1FF0..1FF1 ; UNASSIGNED # <reserved>..<reserved>
2813
+
1FF2..1FF4 ; DISALLOWED # GREEK SMALL LETTER OMEGA WITH VARIA AND YPOG
2814
+
1FF5 ; UNASSIGNED # <reserved>
2815
+
1FF6 ; PVALID # GREEK SMALL LETTER OMEGA WITH PERISPOMENI
2816
+
1FF7..1FFE ; DISALLOWED # GREEK SMALL LETTER OMEGA WITH PERISPOMENI AN
2817
+
1FFF ; UNASSIGNED # <reserved>
2818
+
2000..200B ; DISALLOWED # EN QUAD..ZERO WIDTH SPACE
2819
+
200C..200D ; CONTEXTJ # ZERO WIDTH NON-JOINER..ZERO WIDTH JOINER
2820
+
200E..2064 ; DISALLOWED # LEFT-TO-RIGHT MARK..INVISIBLE PLUS
2821
+
2065..2069 ; UNASSIGNED # <reserved>..<reserved>
2822
+
206A..2071 ; DISALLOWED # INHIBIT SYMMETRIC SWAPPING..SUPERSCRIPT LATI
2823
+
2072..2073 ; UNASSIGNED # <reserved>..<reserved>
2824
+
2074..208E ; DISALLOWED # SUPERSCRIPT FOUR..SUBSCRIPT RIGHT PARENTHESI
2825
+
208F ; UNASSIGNED # <reserved>
2826
+
2090..2094 ; DISALLOWED # LATIN SUBSCRIPT SMALL LETTER A..LATIN SUBSCR
2827
+
2095..209F ; UNASSIGNED # <reserved>..<reserved>
2828
+
20A0..20B8 ; DISALLOWED # EURO-CURRENCY SIGN..TENGE SIGN
2829
+
20B9..20CF ; UNASSIGNED # <reserved>..<reserved>
2830
+
20D0..20F0 ; DISALLOWED # COMBINING LEFT HARPOON ABOVE..COMBINING ASTE
2831
+
20F1..20FF ; UNASSIGNED # <reserved>..<reserved>
2832
+
2100..214D ; DISALLOWED # ACCOUNT OF..AKTIESELSKAB
2833
+
214E ; PVALID # TURNED SMALL F
2834
+
214F..2183 ; DISALLOWED # SYMBOL FOR SAMARITAN SOURCE..ROMAN NUMERAL R
2835
+
2184 ; PVALID # LATIN SMALL LETTER REVERSED C
2836
+
2185..2189 ; DISALLOWED # ROMAN NUMERAL SIX LATE FORM..VULGAR FRACTION
2837
+
218A..218F ; UNASSIGNED # <reserved>..<reserved>
2838
+
2190..23E8 ; DISALLOWED # LEFTWARDS ARROW..DECIMAL EXPONENT SYMBOL
2839
+
23E9..23FF ; UNASSIGNED # <reserved>..<reserved>
2840
+
2400..2426 ; DISALLOWED # SYMBOL FOR NULL..SYMBOL FOR SUBSTITUTE FORM
2841
+
2427..243F ; UNASSIGNED # <reserved>..<reserved>
2842
+
2440..244A ; DISALLOWED # OCR HOOK..OCR DOUBLE BACKSLASH
2843
+
244B..245F ; UNASSIGNED # <reserved>..<reserved>
2844
+
2460..26CD ; DISALLOWED # CIRCLED DIGIT ONE..DISABLED CAR
2845
+
26CE ; UNASSIGNED # <reserved>
2846
+
26CF..26E1 ; DISALLOWED # PICK..RESTRICTED LEFT ENTRY-2
2847
+
26E2 ; UNASSIGNED # <reserved>
2848
+
26E3 ; DISALLOWED # HEAVY CIRCLE WITH STROKE AND TWO DOTS ABOVE
2849
+
26E4..26E7 ; UNASSIGNED # <reserved>..<reserved>
2850
+
26E8..26FF ; DISALLOWED # BLACK CROSS ON SHIELD..WHITE FLAG WITH HORIZ
2851
+
2700 ; UNASSIGNED # <reserved>
2852
+
2701..2704 ; DISALLOWED # UPPER BLADE SCISSORS..WHITE SCISSORS
2853
+
2705 ; UNASSIGNED # <reserved>
2854
+
2706..2709 ; DISALLOWED # TELEPHONE LOCATION SIGN..ENVELOPE
2855
+
2856
+
2857
+
2858
+
Faltstrom Standards Track [Page 51]
2859
+
2860
+
RFC 5892 IDNA Code Points August 2010
2861
+
2862
+
2863
+
270A..270B ; UNASSIGNED # <reserved>..<reserved>
2864
+
270C..2727 ; DISALLOWED # VICTORY HAND..WHITE FOUR POINTED STAR
2865
+
2728 ; UNASSIGNED # <reserved>
2866
+
2729..274B ; DISALLOWED # STRESS OUTLINED WHITE STAR..HEAVY EIGHT TEAR
2867
+
274C ; UNASSIGNED # <reserved>
2868
+
274D ; DISALLOWED # SHADOWED WHITE CIRCLE
2869
+
274E ; UNASSIGNED # <reserved>
2870
+
274F..2752 ; DISALLOWED # LOWER RIGHT DROP-SHADOWED WHITE SQUARE..UPPE
2871
+
2753..2755 ; UNASSIGNED # <reserved>..<reserved>
2872
+
2756..275E ; DISALLOWED # BLACK DIAMOND MINUS WHITE X..HEAVY DOUBLE CO
2873
+
275F..2760 ; UNASSIGNED # <reserved>..<reserved>
2874
+
2761..2794 ; DISALLOWED # CURVED STEM PARAGRAPH SIGN ORNAMENT..HEAVY W
2875
+
2795..2797 ; UNASSIGNED # <reserved>..<reserved>
2876
+
2798..27AF ; DISALLOWED # HEAVY SOUTH EAST ARROW..NOTCHED LOWER RIGHT-
2877
+
27B0 ; UNASSIGNED # <reserved>
2878
+
27B1..27BE ; DISALLOWED # NOTCHED UPPER RIGHT-SHADOWED WHITE RIGHTWARD
2879
+
27BF ; UNASSIGNED # <reserved>
2880
+
27C0..27CA ; DISALLOWED # THREE DIMENSIONAL ANGLE..VERTICAL BAR WITH H
2881
+
27CB ; UNASSIGNED # <reserved>
2882
+
27CC ; DISALLOWED # LONG DIVISION
2883
+
27CD..27CF ; UNASSIGNED # <reserved>..<reserved>
2884
+
27D0..2B4C ; DISALLOWED # WHITE DIAMOND WITH CENTRED DOT..RIGHTWARDS A
2885
+
2B4D..2B4F ; UNASSIGNED # <reserved>..<reserved>
2886
+
2B50..2B59 ; DISALLOWED # WHITE MEDIUM STAR..HEAVY CIRCLED SALTIRE
2887
+
2B5A..2BFF ; UNASSIGNED # <reserved>..<reserved>
2888
+
2C00..2C2E ; DISALLOWED # GLAGOLITIC CAPITAL LETTER AZU..GLAGOLITIC CA
2889
+
2C2F ; UNASSIGNED # <reserved>
2890
+
2C30..2C5E ; PVALID # GLAGOLITIC SMALL LETTER AZU..GLAGOLITIC SMAL
2891
+
2C5F ; UNASSIGNED # <reserved>
2892
+
2C60 ; DISALLOWED # LATIN CAPITAL LETTER L WITH DOUBLE BAR
2893
+
2C61 ; PVALID # LATIN SMALL LETTER L WITH DOUBLE BAR
2894
+
2C62..2C64 ; DISALLOWED # LATIN CAPITAL LETTER L WITH MIDDLE TILDE..LA
2895
+
2C65..2C66 ; PVALID # LATIN SMALL LETTER A WITH STROKE..LATIN SMAL
2896
+
2C67 ; DISALLOWED # LATIN CAPITAL LETTER H WITH DESCENDER
2897
+
2C68 ; PVALID # LATIN SMALL LETTER H WITH DESCENDER
2898
+
2C69 ; DISALLOWED # LATIN CAPITAL LETTER K WITH DESCENDER
2899
+
2C6A ; PVALID # LATIN SMALL LETTER K WITH DESCENDER
2900
+
2C6B ; DISALLOWED # LATIN CAPITAL LETTER Z WITH DESCENDER
2901
+
2C6C ; PVALID # LATIN SMALL LETTER Z WITH DESCENDER
2902
+
2C6D..2C70 ; DISALLOWED # LATIN CAPITAL LETTER ALPHA..LATIN CAPITAL LE
2903
+
2C71 ; PVALID # LATIN SMALL LETTER V WITH RIGHT HOOK
2904
+
2C72 ; DISALLOWED # LATIN CAPITAL LETTER W WITH HOOK
2905
+
2C73..2C74 ; PVALID # LATIN SMALL LETTER W WITH HOOK..LATIN SMALL
2906
+
2C75 ; DISALLOWED # LATIN CAPITAL LETTER HALF H
2907
+
2C76..2C7B ; PVALID # LATIN SMALL LETTER HALF H..LATIN LETTER SMAL
2908
+
2C7C..2C80 ; DISALLOWED # LATIN SUBSCRIPT SMALL LETTER J..COPTIC CAPIT
2909
+
2C81 ; PVALID # COPTIC SMALL LETTER ALFA
2910
+
2C82 ; DISALLOWED # COPTIC CAPITAL LETTER VIDA
2911
+
2912
+
2913
+
2914
+
Faltstrom Standards Track [Page 52]
2915
+
2916
+
RFC 5892 IDNA Code Points August 2010
2917
+
2918
+
2919
+
2C83 ; PVALID # COPTIC SMALL LETTER VIDA
2920
+
2C84 ; DISALLOWED # COPTIC CAPITAL LETTER GAMMA
2921
+
2C85 ; PVALID # COPTIC SMALL LETTER GAMMA
2922
+
2C86 ; DISALLOWED # COPTIC CAPITAL LETTER DALDA
2923
+
2C87 ; PVALID # COPTIC SMALL LETTER DALDA
2924
+
2C88 ; DISALLOWED # COPTIC CAPITAL LETTER EIE
2925
+
2C89 ; PVALID # COPTIC SMALL LETTER EIE
2926
+
2C8A ; DISALLOWED # COPTIC CAPITAL LETTER SOU
2927
+
2C8B ; PVALID # COPTIC SMALL LETTER SOU
2928
+
2C8C ; DISALLOWED # COPTIC CAPITAL LETTER ZATA
2929
+
2C8D ; PVALID # COPTIC SMALL LETTER ZATA
2930
+
2C8E ; DISALLOWED # COPTIC CAPITAL LETTER HATE
2931
+
2C8F ; PVALID # COPTIC SMALL LETTER HATE
2932
+
2C90 ; DISALLOWED # COPTIC CAPITAL LETTER THETHE
2933
+
2C91 ; PVALID # COPTIC SMALL LETTER THETHE
2934
+
2C92 ; DISALLOWED # COPTIC CAPITAL LETTER IAUDA
2935
+
2C93 ; PVALID # COPTIC SMALL LETTER IAUDA
2936
+
2C94 ; DISALLOWED # COPTIC CAPITAL LETTER KAPA
2937
+
2C95 ; PVALID # COPTIC SMALL LETTER KAPA
2938
+
2C96 ; DISALLOWED # COPTIC CAPITAL LETTER LAULA
2939
+
2C97 ; PVALID # COPTIC SMALL LETTER LAULA
2940
+
2C98 ; DISALLOWED # COPTIC CAPITAL LETTER MI
2941
+
2C99 ; PVALID # COPTIC SMALL LETTER MI
2942
+
2C9A ; DISALLOWED # COPTIC CAPITAL LETTER NI
2943
+
2C9B ; PVALID # COPTIC SMALL LETTER NI
2944
+
2C9C ; DISALLOWED # COPTIC CAPITAL LETTER KSI
2945
+
2C9D ; PVALID # COPTIC SMALL LETTER KSI
2946
+
2C9E ; DISALLOWED # COPTIC CAPITAL LETTER O
2947
+
2C9F ; PVALID # COPTIC SMALL LETTER O
2948
+
2CA0 ; DISALLOWED # COPTIC CAPITAL LETTER PI
2949
+
2CA1 ; PVALID # COPTIC SMALL LETTER PI
2950
+
2CA2 ; DISALLOWED # COPTIC CAPITAL LETTER RO
2951
+
2CA3 ; PVALID # COPTIC SMALL LETTER RO
2952
+
2CA4 ; DISALLOWED # COPTIC CAPITAL LETTER SIMA
2953
+
2CA5 ; PVALID # COPTIC SMALL LETTER SIMA
2954
+
2CA6 ; DISALLOWED # COPTIC CAPITAL LETTER TAU
2955
+
2CA7 ; PVALID # COPTIC SMALL LETTER TAU
2956
+
2CA8 ; DISALLOWED # COPTIC CAPITAL LETTER UA
2957
+
2CA9 ; PVALID # COPTIC SMALL LETTER UA
2958
+
2CAA ; DISALLOWED # COPTIC CAPITAL LETTER FI
2959
+
2CAB ; PVALID # COPTIC SMALL LETTER FI
2960
+
2CAC ; DISALLOWED # COPTIC CAPITAL LETTER KHI
2961
+
2CAD ; PVALID # COPTIC SMALL LETTER KHI
2962
+
2CAE ; DISALLOWED # COPTIC CAPITAL LETTER PSI
2963
+
2CAF ; PVALID # COPTIC SMALL LETTER PSI
2964
+
2CB0 ; DISALLOWED # COPTIC CAPITAL LETTER OOU
2965
+
2CB1 ; PVALID # COPTIC SMALL LETTER OOU
2966
+
2CB2 ; DISALLOWED # COPTIC CAPITAL LETTER DIALECT-P ALEF
2967
+
2968
+
2969
+
2970
+
Faltstrom Standards Track [Page 53]
2971
+
2972
+
RFC 5892 IDNA Code Points August 2010
2973
+
2974
+
2975
+
2CB3 ; PVALID # COPTIC SMALL LETTER DIALECT-P ALEF
2976
+
2CB4 ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC AIN
2977
+
2CB5 ; PVALID # COPTIC SMALL LETTER OLD COPTIC AIN
2978
+
2CB6 ; DISALLOWED # COPTIC CAPITAL LETTER CRYPTOGRAMMIC EIE
2979
+
2CB7 ; PVALID # COPTIC SMALL LETTER CRYPTOGRAMMIC EIE
2980
+
2CB8 ; DISALLOWED # COPTIC CAPITAL LETTER DIALECT-P KAPA
2981
+
2CB9 ; PVALID # COPTIC SMALL LETTER DIALECT-P KAPA
2982
+
2CBA ; DISALLOWED # COPTIC CAPITAL LETTER DIALECT-P NI
2983
+
2CBB ; PVALID # COPTIC SMALL LETTER DIALECT-P NI
2984
+
2CBC ; DISALLOWED # COPTIC CAPITAL LETTER CRYPTOGRAMMIC NI
2985
+
2CBD ; PVALID # COPTIC SMALL LETTER CRYPTOGRAMMIC NI
2986
+
2CBE ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC OOU
2987
+
2CBF ; PVALID # COPTIC SMALL LETTER OLD COPTIC OOU
2988
+
2CC0 ; DISALLOWED # COPTIC CAPITAL LETTER SAMPI
2989
+
2CC1 ; PVALID # COPTIC SMALL LETTER SAMPI
2990
+
2CC2 ; DISALLOWED # COPTIC CAPITAL LETTER CROSSED SHEI
2991
+
2CC3 ; PVALID # COPTIC SMALL LETTER CROSSED SHEI
2992
+
2CC4 ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC SHEI
2993
+
2CC5 ; PVALID # COPTIC SMALL LETTER OLD COPTIC SHEI
2994
+
2CC6 ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC ESH
2995
+
2CC7 ; PVALID # COPTIC SMALL LETTER OLD COPTIC ESH
2996
+
2CC8 ; DISALLOWED # COPTIC CAPITAL LETTER AKHMIMIC KHEI
2997
+
2CC9 ; PVALID # COPTIC SMALL LETTER AKHMIMIC KHEI
2998
+
2CCA ; DISALLOWED # COPTIC CAPITAL LETTER DIALECT-P HORI
2999
+
2CCB ; PVALID # COPTIC SMALL LETTER DIALECT-P HORI
3000
+
2CCC ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC HORI
3001
+
2CCD ; PVALID # COPTIC SMALL LETTER OLD COPTIC HORI
3002
+
2CCE ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC HA
3003
+
2CCF ; PVALID # COPTIC SMALL LETTER OLD COPTIC HA
3004
+
2CD0 ; DISALLOWED # COPTIC CAPITAL LETTER L-SHAPED HA
3005
+
2CD1 ; PVALID # COPTIC SMALL LETTER L-SHAPED HA
3006
+
2CD2 ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC HEI
3007
+
2CD3 ; PVALID # COPTIC SMALL LETTER OLD COPTIC HEI
3008
+
2CD4 ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC HAT
3009
+
2CD5 ; PVALID # COPTIC SMALL LETTER OLD COPTIC HAT
3010
+
2CD6 ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC GANGIA
3011
+
2CD7 ; PVALID # COPTIC SMALL LETTER OLD COPTIC GANGIA
3012
+
2CD8 ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC DJA
3013
+
2CD9 ; PVALID # COPTIC SMALL LETTER OLD COPTIC DJA
3014
+
2CDA ; DISALLOWED # COPTIC CAPITAL LETTER OLD COPTIC SHIMA
3015
+
2CDB ; PVALID # COPTIC SMALL LETTER OLD COPTIC SHIMA
3016
+
2CDC ; DISALLOWED # COPTIC CAPITAL LETTER OLD NUBIAN SHIMA
3017
+
2CDD ; PVALID # COPTIC SMALL LETTER OLD NUBIAN SHIMA
3018
+
2CDE ; DISALLOWED # COPTIC CAPITAL LETTER OLD NUBIAN NGI
3019
+
2CDF ; PVALID # COPTIC SMALL LETTER OLD NUBIAN NGI
3020
+
2CE0 ; DISALLOWED # COPTIC CAPITAL LETTER OLD NUBIAN NYI
3021
+
2CE1 ; PVALID # COPTIC SMALL LETTER OLD NUBIAN NYI
3022
+
2CE2 ; DISALLOWED # COPTIC CAPITAL LETTER OLD NUBIAN WAU
3023
+
3024
+
3025
+
3026
+
Faltstrom Standards Track [Page 54]
3027
+
3028
+
RFC 5892 IDNA Code Points August 2010
3029
+
3030
+
3031
+
2CE3..2CE4 ; PVALID # COPTIC SMALL LETTER OLD NUBIAN WAU..COPTIC S
3032
+
2CE5..2CEB ; DISALLOWED # COPTIC SYMBOL MI RO..COPTIC CAPITAL LETTER C
3033
+
2CEC ; PVALID # COPTIC SMALL LETTER CRYPTOGRAMMIC SHEI
3034
+
2CED ; DISALLOWED # COPTIC CAPITAL LETTER CRYPTOGRAMMIC GANGIA
3035
+
2CEE..2CF1 ; PVALID # COPTIC SMALL LETTER CRYPTOGRAMMIC GANGIA..CO
3036
+
2CF2..2CF8 ; UNASSIGNED # <reserved>..<reserved>
3037
+
2CF9..2CFF ; DISALLOWED # COPTIC OLD NUBIAN FULL STOP..COPTIC MORPHOLO
3038
+
2D00..2D25 ; PVALID # GEORGIAN SMALL LETTER AN..GEORGIAN SMALL LET
3039
+
2D26..2D2F ; UNASSIGNED # <reserved>..<reserved>
3040
+
2D30..2D65 ; PVALID # TIFINAGH LETTER YA..TIFINAGH LETTER YAZZ
3041
+
2D66..2D6E ; UNASSIGNED # <reserved>..<reserved>
3042
+
2D6F ; DISALLOWED # TIFINAGH MODIFIER LETTER LABIALIZATION MARK
3043
+
2D70..2D7F ; UNASSIGNED # <reserved>..<reserved>
3044
+
2D80..2D96 ; PVALID # ETHIOPIC SYLLABLE LOA..ETHIOPIC SYLLABLE GGW
3045
+
2D97..2D9F ; UNASSIGNED # <reserved>..<reserved>
3046
+
2DA0..2DA6 ; PVALID # ETHIOPIC SYLLABLE SSA..ETHIOPIC SYLLABLE SSO
3047
+
2DA7 ; UNASSIGNED # <reserved>
3048
+
2DA8..2DAE ; PVALID # ETHIOPIC SYLLABLE CCA..ETHIOPIC SYLLABLE CCO
3049
+
2DAF ; UNASSIGNED # <reserved>
3050
+
2DB0..2DB6 ; PVALID # ETHIOPIC SYLLABLE ZZA..ETHIOPIC SYLLABLE ZZO
3051
+
2DB7 ; UNASSIGNED # <reserved>
3052
+
2DB8..2DBE ; PVALID # ETHIOPIC SYLLABLE CCHA..ETHIOPIC SYLLABLE CC
3053
+
2DBF ; UNASSIGNED # <reserved>
3054
+
2DC0..2DC6 ; PVALID # ETHIOPIC SYLLABLE QYA..ETHIOPIC SYLLABLE QYO
3055
+
2DC7 ; UNASSIGNED # <reserved>
3056
+
2DC8..2DCE ; PVALID # ETHIOPIC SYLLABLE KYA..ETHIOPIC SYLLABLE KYO
3057
+
2DCF ; UNASSIGNED # <reserved>
3058
+
2DD0..2DD6 ; PVALID # ETHIOPIC SYLLABLE XYA..ETHIOPIC SYLLABLE XYO
3059
+
2DD7 ; UNASSIGNED # <reserved>
3060
+
2DD8..2DDE ; PVALID # ETHIOPIC SYLLABLE GYA..ETHIOPIC SYLLABLE GYO
3061
+
2DDF ; UNASSIGNED # <reserved>
3062
+
2DE0..2DFF ; PVALID # COMBINING CYRILLIC LETTER BE..COMBINING CYRI
3063
+
2E00..2E2E ; DISALLOWED # RIGHT ANGLE SUBSTITUTION MARKER..REVERSED QU
3064
+
2E2F ; PVALID # VERTICAL TILDE
3065
+
2E30..2E31 ; DISALLOWED # RING POINT..WORD SEPARATOR MIDDLE DOT
3066
+
2E32..2E7F ; UNASSIGNED # <reserved>..<reserved>
3067
+
2E80..2E99 ; DISALLOWED # CJK RADICAL REPEAT..CJK RADICAL RAP
3068
+
2E9A ; UNASSIGNED # <reserved>
3069
+
2E9B..2EF3 ; DISALLOWED # CJK RADICAL CHOKE..CJK RADICAL C-SIMPLIFIED
3070
+
2EF4..2EFF ; UNASSIGNED # <reserved>..<reserved>
3071
+
2F00..2FD5 ; DISALLOWED # KANGXI RADICAL ONE..KANGXI RADICAL FLUTE
3072
+
2FD6..2FEF ; UNASSIGNED # <reserved>..<reserved>
3073
+
2FF0..2FFB ; DISALLOWED # IDEOGRAPHIC DESCRIPTION CHARACTER LEFT TO RI
3074
+
2FFC..2FFF ; UNASSIGNED # <reserved>..<reserved>
3075
+
3000..3004 ; DISALLOWED # IDEOGRAPHIC SPACE..JAPANESE INDUSTRIAL STAND
3076
+
3005..3007 ; PVALID # IDEOGRAPHIC ITERATION MARK..IDEOGRAPHIC NUMB
3077
+
3008..3029 ; DISALLOWED # LEFT ANGLE BRACKET..HANGZHOU NUMERAL NINE
3078
+
302A..302D ; PVALID # IDEOGRAPHIC LEVEL TONE MARK..IDEOGRAPHIC ENT
3079
+
3080
+
3081
+
3082
+
Faltstrom Standards Track [Page 55]
3083
+
3084
+
RFC 5892 IDNA Code Points August 2010
3085
+
3086
+
3087
+
302E..303B ; DISALLOWED # HANGUL SINGLE DOT TONE MARK..VERTICAL IDEOGR
3088
+
303C ; PVALID # MASU MARK
3089
+
303D..303F ; DISALLOWED # PART ALTERNATION MARK..IDEOGRAPHIC HALF FILL
3090
+
3040 ; UNASSIGNED # <reserved>
3091
+
3041..3096 ; PVALID # HIRAGANA LETTER SMALL A..HIRAGANA LETTER SMA
3092
+
3097..3098 ; UNASSIGNED # <reserved>..<reserved>
3093
+
3099..309A ; PVALID # COMBINING KATAKANA-HIRAGANA VOICED SOUND MAR
3094
+
309B..309C ; DISALLOWED # KATAKANA-HIRAGANA VOICED SOUND MARK..KATAKAN
3095
+
309D..309E ; PVALID # HIRAGANA ITERATION MARK..HIRAGANA VOICED ITE
3096
+
309F..30A0 ; DISALLOWED # HIRAGANA DIGRAPH YORI..KATAKANA-HIRAGANA DOU
3097
+
30A1..30FA ; PVALID # KATAKANA LETTER SMALL A..KATAKANA LETTER VO
3098
+
30FB ; CONTEXTO # KATAKANA MIDDLE DOT
3099
+
30FC..30FE ; PVALID # KATAKANA-HIRAGANA PROLONGED SOUND MARK..KATA
3100
+
30FF ; DISALLOWED # KATAKANA DIGRAPH KOTO
3101
+
3100..3104 ; UNASSIGNED # <reserved>..<reserved>
3102
+
3105..312D ; PVALID # BOPOMOFO LETTER B..BOPOMOFO LETTER IH
3103
+
312E..3130 ; UNASSIGNED # <reserved>..<reserved>
3104
+
3131..318E ; DISALLOWED # HANGUL LETTER KIYEOK..HANGUL LETTER ARAEAE
3105
+
318F ; UNASSIGNED # <reserved>
3106
+
3190..319F ; DISALLOWED # IDEOGRAPHIC ANNOTATION LINKING MARK..IDEOGRA
3107
+
31A0..31B7 ; PVALID # BOPOMOFO LETTER BU..BOPOMOFO FINAL LETTER H
3108
+
31B8..31BF ; UNASSIGNED # <reserved>..<reserved>
3109
+
31C0..31E3 ; DISALLOWED # CJK STROKE T..CJK STROKE Q
3110
+
31E4..31EF ; UNASSIGNED # <reserved>..<reserved>
3111
+
31F0..31FF ; PVALID # KATAKANA LETTER SMALL KU..KATAKANA LETTER SM
3112
+
3200..321E ; DISALLOWED # PARENTHESIZED HANGUL KIYEOK..PARENTHESIZED K
3113
+
321F ; UNASSIGNED # <reserved>
3114
+
3220..32FE ; DISALLOWED # PARENTHESIZED IDEOGRAPH ONE..CIRCLED KATAKAN
3115
+
32FF ; UNASSIGNED # <reserved>
3116
+
3300..33FF ; DISALLOWED # SQUARE APAATO..SQUARE GAL
3117
+
3400..4DB5 ; PVALID # <CJK Ideograph Extension A>..<CJK Ideograph
3118
+
4DB6..4DBF ; UNASSIGNED # <reserved>..<reserved>
3119
+
4DC0..4DFF ; DISALLOWED # HEXAGRAM FOR THE CREATIVE HEAVEN..HEXAGRAM F
3120
+
4E00..9FCB ; PVALID # <CJK Ideograph>..<CJK Ideograph>
3121
+
9FCC..9FFF ; UNASSIGNED # <reserved>..<reserved>
3122
+
A000..A48C ; PVALID # YI SYLLABLE IT..YI SYLLABLE YYR
3123
+
A48D..A48F ; UNASSIGNED # <reserved>..<reserved>
3124
+
A490..A4C6 ; DISALLOWED # YI RADICAL QOT..YI RADICAL KE
3125
+
A4C7..A4CF ; UNASSIGNED # <reserved>..<reserved>
3126
+
A4D0..A4FD ; PVALID # LISU LETTER BA..LISU LETTER TONE MYA JEU
3127
+
A4FE..A4FF ; DISALLOWED # LISU PUNCTUATION COMMA..LISU PUNCTUATION FUL
3128
+
A500..A60C ; PVALID # VAI SYLLABLE EE..VAI SYLLABLE LENGTHENER
3129
+
A60D..A60F ; DISALLOWED # VAI COMMA..VAI QUESTION MARK
3130
+
A610..A62B ; PVALID # VAI SYLLABLE NDOLE FA..VAI SYLLABLE NDOLE DO
3131
+
A62C..A63F ; UNASSIGNED # <reserved>..<reserved>
3132
+
A640 ; DISALLOWED # CYRILLIC CAPITAL LETTER ZEMLYA
3133
+
A641 ; PVALID # CYRILLIC SMALL LETTER ZEMLYA
3134
+
A642 ; DISALLOWED # CYRILLIC CAPITAL LETTER DZELO
3135
+
3136
+
3137
+
3138
+
Faltstrom Standards Track [Page 56]
3139
+
3140
+
RFC 5892 IDNA Code Points August 2010
3141
+
3142
+
3143
+
A643 ; PVALID # CYRILLIC SMALL LETTER DZELO
3144
+
A644 ; DISALLOWED # CYRILLIC CAPITAL LETTER REVERSED DZE
3145
+
A645 ; PVALID # CYRILLIC SMALL LETTER REVERSED DZE
3146
+
A646 ; DISALLOWED # CYRILLIC CAPITAL LETTER IOTA
3147
+
A647 ; PVALID # CYRILLIC SMALL LETTER IOTA
3148
+
A648 ; DISALLOWED # CYRILLIC CAPITAL LETTER DJERV
3149
+
A649 ; PVALID # CYRILLIC SMALL LETTER DJERV
3150
+
A64A ; DISALLOWED # CYRILLIC CAPITAL LETTER MONOGRAPH UK
3151
+
A64B ; PVALID # CYRILLIC SMALL LETTER MONOGRAPH UK
3152
+
A64C ; DISALLOWED # CYRILLIC CAPITAL LETTER BROAD OMEGA
3153
+
A64D ; PVALID # CYRILLIC SMALL LETTER BROAD OMEGA
3154
+
A64E ; DISALLOWED # CYRILLIC CAPITAL LETTER NEUTRAL YER
3155
+
A64F ; PVALID # CYRILLIC SMALL LETTER NEUTRAL YER
3156
+
A650 ; DISALLOWED # CYRILLIC CAPITAL LETTER YERU WITH BACK YER
3157
+
A651 ; PVALID # CYRILLIC SMALL LETTER YERU WITH BACK YER
3158
+
A652 ; DISALLOWED # CYRILLIC CAPITAL LETTER IOTIFIED YAT
3159
+
A653 ; PVALID # CYRILLIC SMALL LETTER IOTIFIED YAT
3160
+
A654 ; DISALLOWED # CYRILLIC CAPITAL LETTER REVERSED YU
3161
+
A655 ; PVALID # CYRILLIC SMALL LETTER REVERSED YU
3162
+
A656 ; DISALLOWED # CYRILLIC CAPITAL LETTER IOTIFIED A
3163
+
A657 ; PVALID # CYRILLIC SMALL LETTER IOTIFIED A
3164
+
A658 ; DISALLOWED # CYRILLIC CAPITAL LETTER CLOSED LITTLE YUS
3165
+
A659 ; PVALID # CYRILLIC SMALL LETTER CLOSED LITTLE YUS
3166
+
A65A ; DISALLOWED # CYRILLIC CAPITAL LETTER BLENDED YUS
3167
+
A65B ; PVALID # CYRILLIC SMALL LETTER BLENDED YUS
3168
+
A65C ; DISALLOWED # CYRILLIC CAPITAL LETTER IOTIFIED CLOSED LITT
3169
+
A65D ; PVALID # CYRILLIC SMALL LETTER IOTIFIED CLOSED LITTLE
3170
+
A65E ; DISALLOWED # CYRILLIC CAPITAL LETTER YN
3171
+
A65F ; PVALID # CYRILLIC SMALL LETTER YN
3172
+
A660..A661 ; UNASSIGNED # <reserved>..<reserved>
3173
+
A662 ; DISALLOWED # CYRILLIC CAPITAL LETTER SOFT DE
3174
+
A663 ; PVALID # CYRILLIC SMALL LETTER SOFT DE
3175
+
A664 ; DISALLOWED # CYRILLIC CAPITAL LETTER SOFT EL
3176
+
A665 ; PVALID # CYRILLIC SMALL LETTER SOFT EL
3177
+
A666 ; DISALLOWED # CYRILLIC CAPITAL LETTER SOFT EM
3178
+
A667 ; PVALID # CYRILLIC SMALL LETTER SOFT EM
3179
+
A668 ; DISALLOWED # CYRILLIC CAPITAL LETTER MONOCULAR O
3180
+
A669 ; PVALID # CYRILLIC SMALL LETTER MONOCULAR O
3181
+
A66A ; DISALLOWED # CYRILLIC CAPITAL LETTER BINOCULAR O
3182
+
A66B ; PVALID # CYRILLIC SMALL LETTER BINOCULAR O
3183
+
A66C ; DISALLOWED # CYRILLIC CAPITAL LETTER DOUBLE MONOCULAR O
3184
+
A66D..A66F ; PVALID # CYRILLIC SMALL LETTER DOUBLE MONOCULAR O..CO
3185
+
A670..A673 ; DISALLOWED # COMBINING CYRILLIC TEN MILLIONS SIGN..SLAVON
3186
+
A674..A67B ; UNASSIGNED # <reserved>..<reserved>
3187
+
A67C..A67D ; PVALID # COMBINING CYRILLIC KAVYKA..COMBINING CYRILLI
3188
+
A67E ; DISALLOWED # CYRILLIC KAVYKA
3189
+
A67F ; PVALID # CYRILLIC PAYEROK
3190
+
A680 ; DISALLOWED # CYRILLIC CAPITAL LETTER DWE
3191
+
3192
+
3193
+
3194
+
Faltstrom Standards Track [Page 57]
3195
+
3196
+
RFC 5892 IDNA Code Points August 2010
3197
+
3198
+
3199
+
A681 ; PVALID # CYRILLIC SMALL LETTER DWE
3200
+
A682 ; DISALLOWED # CYRILLIC CAPITAL LETTER DZWE
3201
+
A683 ; PVALID # CYRILLIC SMALL LETTER DZWE
3202
+
A684 ; DISALLOWED # CYRILLIC CAPITAL LETTER ZHWE
3203
+
A685 ; PVALID # CYRILLIC SMALL LETTER ZHWE
3204
+
A686 ; DISALLOWED # CYRILLIC CAPITAL LETTER CCHE
3205
+
A687 ; PVALID # CYRILLIC SMALL LETTER CCHE
3206
+
A688 ; DISALLOWED # CYRILLIC CAPITAL LETTER DZZE
3207
+
A689 ; PVALID # CYRILLIC SMALL LETTER DZZE
3208
+
A68A ; DISALLOWED # CYRILLIC CAPITAL LETTER TE WITH MIDDLE HOOK
3209
+
A68B ; PVALID # CYRILLIC SMALL LETTER TE WITH MIDDLE HOOK
3210
+
A68C ; DISALLOWED # CYRILLIC CAPITAL LETTER TWE
3211
+
A68D ; PVALID # CYRILLIC SMALL LETTER TWE
3212
+
A68E ; DISALLOWED # CYRILLIC CAPITAL LETTER TSWE
3213
+
A68F ; PVALID # CYRILLIC SMALL LETTER TSWE
3214
+
A690 ; DISALLOWED # CYRILLIC CAPITAL LETTER TSSE
3215
+
A691 ; PVALID # CYRILLIC SMALL LETTER TSSE
3216
+
A692 ; DISALLOWED # CYRILLIC CAPITAL LETTER TCHE
3217
+
A693 ; PVALID # CYRILLIC SMALL LETTER TCHE
3218
+
A694 ; DISALLOWED # CYRILLIC CAPITAL LETTER HWE
3219
+
A695 ; PVALID # CYRILLIC SMALL LETTER HWE
3220
+
A696 ; DISALLOWED # CYRILLIC CAPITAL LETTER SHWE
3221
+
A697 ; PVALID # CYRILLIC SMALL LETTER SHWE
3222
+
A698..A69F ; UNASSIGNED # <reserved>..<reserved>
3223
+
A6A0..A6E5 ; PVALID # BAMUM LETTER A..BAMUM LETTER KI
3224
+
A6E6..A6EF ; DISALLOWED # BAMUM LETTER MO..BAMUM LETTER KOGHOM
3225
+
A6F0..A6F1 ; PVALID # BAMUM COMBINING MARK KOQNDON..BAMUM COMBININ
3226
+
A6F2..A6F7 ; DISALLOWED # BAMUM NJAEMLI..BAMUM QUESTION MARK
3227
+
A6F8..A6FF ; UNASSIGNED # <reserved>..<reserved>
3228
+
A700..A716 ; DISALLOWED # MODIFIER LETTER CHINESE TONE YIN PING..MODIF
3229
+
A717..A71F ; PVALID # MODIFIER LETTER DOT VERTICAL BAR..MODIFIER L
3230
+
A720..A722 ; DISALLOWED # MODIFIER LETTER STRESS AND HIGH TONE..LATIN
3231
+
A723 ; PVALID # LATIN SMALL LETTER EGYPTOLOGICAL ALEF
3232
+
A724 ; DISALLOWED # LATIN CAPITAL LETTER EGYPTOLOGICAL AIN
3233
+
A725 ; PVALID # LATIN SMALL LETTER EGYPTOLOGICAL AIN
3234
+
A726 ; DISALLOWED # LATIN CAPITAL LETTER HENG
3235
+
A727 ; PVALID # LATIN SMALL LETTER HENG
3236
+
A728 ; DISALLOWED # LATIN CAPITAL LETTER TZ
3237
+
A729 ; PVALID # LATIN SMALL LETTER TZ
3238
+
A72A ; DISALLOWED # LATIN CAPITAL LETTER TRESILLO
3239
+
A72B ; PVALID # LATIN SMALL LETTER TRESILLO
3240
+
A72C ; DISALLOWED # LATIN CAPITAL LETTER CUATRILLO
3241
+
A72D ; PVALID # LATIN SMALL LETTER CUATRILLO
3242
+
A72E ; DISALLOWED # LATIN CAPITAL LETTER CUATRILLO WITH COMMA
3243
+
A72F..A731 ; PVALID # LATIN SMALL LETTER CUATRILLO WITH COMMA..LAT
3244
+
A732 ; DISALLOWED # LATIN CAPITAL LETTER AA
3245
+
A733 ; PVALID # LATIN SMALL LETTER AA
3246
+
A734 ; DISALLOWED # LATIN CAPITAL LETTER AO
3247
+
3248
+
3249
+
3250
+
Faltstrom Standards Track [Page 58]
3251
+
3252
+
RFC 5892 IDNA Code Points August 2010
3253
+
3254
+
3255
+
A735 ; PVALID # LATIN SMALL LETTER AO
3256
+
A736 ; DISALLOWED # LATIN CAPITAL LETTER AU
3257
+
A737 ; PVALID # LATIN SMALL LETTER AU
3258
+
A738 ; DISALLOWED # LATIN CAPITAL LETTER AV
3259
+
A739 ; PVALID # LATIN SMALL LETTER AV
3260
+
A73A ; DISALLOWED # LATIN CAPITAL LETTER AV WITH HORIZONTAL BAR
3261
+
A73B ; PVALID # LATIN SMALL LETTER AV WITH HORIZONTAL BAR
3262
+
A73C ; DISALLOWED # LATIN CAPITAL LETTER AY
3263
+
A73D ; PVALID # LATIN SMALL LETTER AY
3264
+
A73E ; DISALLOWED # LATIN CAPITAL LETTER REVERSED C WITH DOT
3265
+
A73F ; PVALID # LATIN SMALL LETTER REVERSED C WITH DOT
3266
+
A740 ; DISALLOWED # LATIN CAPITAL LETTER K WITH STROKE
3267
+
A741 ; PVALID # LATIN SMALL LETTER K WITH STROKE
3268
+
A742 ; DISALLOWED # LATIN CAPITAL LETTER K WITH DIAGONAL STROKE
3269
+
A743 ; PVALID # LATIN SMALL LETTER K WITH DIAGONAL STROKE
3270
+
A744 ; DISALLOWED # LATIN CAPITAL LETTER K WITH STROKE AND DIAGO
3271
+
A745 ; PVALID # LATIN SMALL LETTER K WITH STROKE AND DIAGONA
3272
+
A746 ; DISALLOWED # LATIN CAPITAL LETTER BROKEN L
3273
+
A747 ; PVALID # LATIN SMALL LETTER BROKEN L
3274
+
A748 ; DISALLOWED # LATIN CAPITAL LETTER L WITH HIGH STROKE
3275
+
A749 ; PVALID # LATIN SMALL LETTER L WITH HIGH STROKE
3276
+
A74A ; DISALLOWED # LATIN CAPITAL LETTER O WITH LONG STROKE OVER
3277
+
A74B ; PVALID # LATIN SMALL LETTER O WITH LONG STROKE OVERLA
3278
+
A74C ; DISALLOWED # LATIN CAPITAL LETTER O WITH LOOP
3279
+
A74D ; PVALID # LATIN SMALL LETTER O WITH LOOP
3280
+
A74E ; DISALLOWED # LATIN CAPITAL LETTER OO
3281
+
A74F ; PVALID # LATIN SMALL LETTER OO
3282
+
A750 ; DISALLOWED # LATIN CAPITAL LETTER P WITH STROKE THROUGH D
3283
+
A751 ; PVALID # LATIN SMALL LETTER P WITH STROKE THROUGH DES
3284
+
A752 ; DISALLOWED # LATIN CAPITAL LETTER P WITH FLOURISH
3285
+
A753 ; PVALID # LATIN SMALL LETTER P WITH FLOURISH
3286
+
A754 ; DISALLOWED # LATIN CAPITAL LETTER P WITH SQUIRREL TAIL
3287
+
A755 ; PVALID # LATIN SMALL LETTER P WITH SQUIRREL TAIL
3288
+
A756 ; DISALLOWED # LATIN CAPITAL LETTER Q WITH STROKE THROUGH D
3289
+
A757 ; PVALID # LATIN SMALL LETTER Q WITH STROKE THROUGH DES
3290
+
A758 ; DISALLOWED # LATIN CAPITAL LETTER Q WITH DIAGONAL STROKE
3291
+
A759 ; PVALID # LATIN SMALL LETTER Q WITH DIAGONAL STROKE
3292
+
A75A ; DISALLOWED # LATIN CAPITAL LETTER R ROTUNDA
3293
+
A75B ; PVALID # LATIN SMALL LETTER R ROTUNDA
3294
+
A75C ; DISALLOWED # LATIN CAPITAL LETTER RUM ROTUNDA
3295
+
A75D ; PVALID # LATIN SMALL LETTER RUM ROTUNDA
3296
+
A75E ; DISALLOWED # LATIN CAPITAL LETTER V WITH DIAGONAL STROKE
3297
+
A75F ; PVALID # LATIN SMALL LETTER V WITH DIAGONAL STROKE
3298
+
A760 ; DISALLOWED # LATIN CAPITAL LETTER VY
3299
+
A761 ; PVALID # LATIN SMALL LETTER VY
3300
+
A762 ; DISALLOWED # LATIN CAPITAL LETTER VISIGOTHIC Z
3301
+
A763 ; PVALID # LATIN SMALL LETTER VISIGOTHIC Z
3302
+
A764 ; DISALLOWED # LATIN CAPITAL LETTER THORN WITH STROKE
3303
+
3304
+
3305
+
3306
+
Faltstrom Standards Track [Page 59]
3307
+
3308
+
RFC 5892 IDNA Code Points August 2010
3309
+
3310
+
3311
+
A765 ; PVALID # LATIN SMALL LETTER THORN WITH STROKE
3312
+
A766 ; DISALLOWED # LATIN CAPITAL LETTER THORN WITH STROKE THROU
3313
+
A767 ; PVALID # LATIN SMALL LETTER THORN WITH STROKE THROUGH
3314
+
A768 ; DISALLOWED # LATIN CAPITAL LETTER VEND
3315
+
A769 ; PVALID # LATIN SMALL LETTER VEND
3316
+
A76A ; DISALLOWED # LATIN CAPITAL LETTER ET
3317
+
A76B ; PVALID # LATIN SMALL LETTER ET
3318
+
A76C ; DISALLOWED # LATIN CAPITAL LETTER IS
3319
+
A76D ; PVALID # LATIN SMALL LETTER IS
3320
+
A76E ; DISALLOWED # LATIN CAPITAL LETTER CON
3321
+
A76F ; PVALID # LATIN SMALL LETTER CON
3322
+
A770 ; DISALLOWED # MODIFIER LETTER US
3323
+
A771..A778 ; PVALID # LATIN SMALL LETTER DUM..LATIN SMALL LETTER U
3324
+
A779 ; DISALLOWED # LATIN CAPITAL LETTER INSULAR D
3325
+
A77A ; PVALID # LATIN SMALL LETTER INSULAR D
3326
+
A77B ; DISALLOWED # LATIN CAPITAL LETTER INSULAR F
3327
+
A77C ; PVALID # LATIN SMALL LETTER INSULAR F
3328
+
A77D..A77E ; DISALLOWED # LATIN CAPITAL LETTER INSULAR G..LATIN CAPITA
3329
+
A77F ; PVALID # LATIN SMALL LETTER TURNED INSULAR G
3330
+
A780 ; DISALLOWED # LATIN CAPITAL LETTER TURNED L
3331
+
A781 ; PVALID # LATIN SMALL LETTER TURNED L
3332
+
A782 ; DISALLOWED # LATIN CAPITAL LETTER INSULAR R
3333
+
A783 ; PVALID # LATIN SMALL LETTER INSULAR R
3334
+
A784 ; DISALLOWED # LATIN CAPITAL LETTER INSULAR S
3335
+
A785 ; PVALID # LATIN SMALL LETTER INSULAR S
3336
+
A786 ; DISALLOWED # LATIN CAPITAL LETTER INSULAR T
3337
+
A787..A788 ; PVALID # LATIN SMALL LETTER INSULAR T..MODIFIER LETTE
3338
+
A789..A78B ; DISALLOWED # MODIFIER LETTER COLON..LATIN CAPITAL LETTER
3339
+
A78C ; PVALID # LATIN SMALL LETTER SALTILLO
3340
+
A78D..A7FA ; UNASSIGNED # <reserved>..<reserved>
3341
+
A7FB..A827 ; PVALID # LATIN EPIGRAPHIC LETTER REVERSED F..SYLOTI N
3342
+
A828..A82B ; DISALLOWED # SYLOTI NAGRI POETRY MARK-1..SYLOTI NAGRI POE
3343
+
A82C..A82F ; UNASSIGNED # <reserved>..<reserved>
3344
+
A830..A839 ; DISALLOWED # NORTH INDIC FRACTION ONE QUARTER..NORTH INDI
3345
+
A83A..A83F ; UNASSIGNED # <reserved>..<reserved>
3346
+
A840..A873 ; PVALID # PHAGS-PA LETTER KA..PHAGS-PA LETTER CANDRABI
3347
+
A874..A877 ; DISALLOWED # PHAGS-PA SINGLE HEAD MARK..PHAGS-PA MARK DOU
3348
+
A878..A87F ; UNASSIGNED # <reserved>..<reserved>
3349
+
A880..A8C4 ; PVALID # SAURASHTRA SIGN ANUSVARA..SAURASHTRA SIGN VI
3350
+
A8C5..A8CD ; UNASSIGNED # <reserved>..<reserved>
3351
+
A8CE..A8CF ; DISALLOWED # SAURASHTRA DANDA..SAURASHTRA DOUBLE DANDA
3352
+
A8D0..A8D9 ; PVALID # SAURASHTRA DIGIT ZERO..SAURASHTRA DIGIT NINE
3353
+
A8DA..A8DF ; UNASSIGNED # <reserved>..<reserved>
3354
+
A8E0..A8F7 ; PVALID # COMBINING DEVANAGARI DIGIT ZERO..DEVANAGARI
3355
+
A8F8..A8FA ; DISALLOWED # DEVANAGARI SIGN PUSHPIKA..DEVANAGARI CARET
3356
+
A8FB ; PVALID # DEVANAGARI HEADSTROKE
3357
+
A8FC..A8FF ; UNASSIGNED # <reserved>..<reserved>
3358
+
A900..A92D ; PVALID # KAYAH LI DIGIT ZERO..KAYAH LI TONE CALYA PLO
3359
+
3360
+
3361
+
3362
+
Faltstrom Standards Track [Page 60]
3363
+
3364
+
RFC 5892 IDNA Code Points August 2010
3365
+
3366
+
3367
+
A92E..A92F ; DISALLOWED # KAYAH LI SIGN CWI..KAYAH LI SIGN SHYA
3368
+
A930..A953 ; PVALID # REJANG LETTER KA..REJANG VIRAMA
3369
+
A954..A95E ; UNASSIGNED # <reserved>..<reserved>
3370
+
A95F..A97C ; DISALLOWED # REJANG SECTION MARK..HANGUL CHOSEONG SSANGYE
3371
+
A97D..A97F ; UNASSIGNED # <reserved>..<reserved>
3372
+
A980..A9C0 ; PVALID # JAVANESE SIGN PANYANGGA..JAVANESE PANGKON
3373
+
A9C1..A9CD ; DISALLOWED # JAVANESE LEFT RERENGGAN..JAVANESE TURNED PAD
3374
+
A9CE ; UNASSIGNED # <reserved>
3375
+
A9CF..A9D9 ; PVALID # JAVANESE PANGRANGKEP..JAVANESE DIGIT NINE
3376
+
A9DA..A9DD ; UNASSIGNED # <reserved>..<reserved>
3377
+
A9DE..A9DF ; DISALLOWED # JAVANESE PADA TIRTA TUMETES..JAVANESE PADA I
3378
+
A9E0..A9FF ; UNASSIGNED # <reserved>..<reserved>
3379
+
AA00..AA36 ; PVALID # CHAM LETTER A..CHAM CONSONANT SIGN WA
3380
+
AA37..AA3F ; UNASSIGNED # <reserved>..<reserved>
3381
+
AA40..AA4D ; PVALID # CHAM LETTER FINAL K..CHAM CONSONANT SIGN FIN
3382
+
AA4E..AA4F ; UNASSIGNED # <reserved>..<reserved>
3383
+
AA50..AA59 ; PVALID # CHAM DIGIT ZERO..CHAM DIGIT NINE
3384
+
AA5A..AA5B ; UNASSIGNED # <reserved>..<reserved>
3385
+
AA5C..AA5F ; DISALLOWED # CHAM PUNCTUATION SPIRAL..CHAM PUNCTUATION TR
3386
+
AA60..AA76 ; PVALID # MYANMAR LETTER KHAMTI GA..MYANMAR LOGOGRAM K
3387
+
AA77..AA79 ; DISALLOWED # MYANMAR SYMBOL AITON EXCLAMATION..MYANMAR SY
3388
+
AA7A..AA7B ; PVALID # MYANMAR LETTER AITON RA..MYANMAR SIGN PAO KA
3389
+
AA7C..AA7F ; UNASSIGNED # <reserved>..<reserved>
3390
+
AA80..AAC2 ; PVALID # TAI VIET LETTER LOW KO..TAI VIET TONE MAI SO
3391
+
AAC3..AADA ; UNASSIGNED # <reserved>..<reserved>
3392
+
AADB..AADD ; PVALID # TAI VIET SYMBOL KON..TAI VIET SYMBOL SAM
3393
+
AADE..AADF ; DISALLOWED # TAI VIET SYMBOL HO HOI..TAI VIET SYMBOL KOI
3394
+
AAE0..ABBF ; UNASSIGNED # <reserved>..<reserved>
3395
+
ABC0..ABEA ; PVALID # MEETEI MAYEK LETTER KOK..MEETEI MAYEK VOWEL
3396
+
ABEB ; DISALLOWED # MEETEI MAYEK CHEIKHEI
3397
+
ABEC..ABED ; PVALID # MEETEI MAYEK LUM IYEK..MEETEI MAYEK APUN IYE
3398
+
ABEE..ABEF ; UNASSIGNED # <reserved>..<reserved>
3399
+
ABF0..ABF9 ; PVALID # MEETEI MAYEK DIGIT ZERO..MEETEI MAYEK DIGIT
3400
+
ABFA..ABFF ; UNASSIGNED # <reserved>..<reserved>
3401
+
AC00..D7A3 ; PVALID # <Hangul Syllable>..<Hangul Syllable>
3402
+
D7A4..D7AF ; UNASSIGNED # <reserved>..<reserved>
3403
+
D7B0..D7C6 ; DISALLOWED # HANGUL JUNGSEONG O-YEO..HANGUL JUNGSEONG ARA
3404
+
D7C7..D7CA ; UNASSIGNED # <reserved>..<reserved>
3405
+
D7CB..D7FB ; DISALLOWED # HANGUL JONGSEONG NIEUN-RIEUL..HANGUL JONGSEO
3406
+
D7FC..D7FF ; UNASSIGNED # <reserved>..<reserved>
3407
+
D800..FA0D ; DISALLOWED # <Non Private Use High Surrogate>..CJK COMPAT
3408
+
FA0E..FA0F ; PVALID # CJK COMPATIBILITY IDEOGRAPH-FA0E..CJK COMPAT
3409
+
FA10 ; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-FA10
3410
+
FA11 ; PVALID # CJK COMPATIBILITY IDEOGRAPH-FA11
3411
+
FA12 ; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-FA12
3412
+
FA13..FA14 ; PVALID # CJK COMPATIBILITY IDEOGRAPH-FA13..CJK COMPAT
3413
+
FA15..FA1E ; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-FA15..CJK COMPAT
3414
+
FA1F ; PVALID # CJK COMPATIBILITY IDEOGRAPH-FA1F
3415
+
3416
+
3417
+
3418
+
Faltstrom Standards Track [Page 61]
3419
+
3420
+
RFC 5892 IDNA Code Points August 2010
3421
+
3422
+
3423
+
FA20 ; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-FA20
3424
+
FA21 ; PVALID # CJK COMPATIBILITY IDEOGRAPH-FA21
3425
+
FA22 ; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-FA22
3426
+
FA23..FA24 ; PVALID # CJK COMPATIBILITY IDEOGRAPH-FA23..CJK COMPAT
3427
+
FA25..FA26 ; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-FA25..CJK COMPAT
3428
+
FA27..FA29 ; PVALID # CJK COMPATIBILITY IDEOGRAPH-FA27..CJK COMPAT
3429
+
FA2A..FA2D ; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-FA2A..CJK COMPAT
3430
+
FA2E..FA2F ; UNASSIGNED # <reserved>..<reserved>
3431
+
FA30..FA6D ; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-FA30..CJK COMPAT
3432
+
FA6E..FA6F ; UNASSIGNED # <reserved>..<reserved>
3433
+
FA70..FAD9 ; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-FA70..CJK COMPAT
3434
+
FADA..FAFF ; UNASSIGNED # <reserved>..<reserved>
3435
+
FB00..FB06 ; DISALLOWED # LATIN SMALL LIGATURE FF..LATIN SMALL LIGATUR
3436
+
FB07..FB12 ; UNASSIGNED # <reserved>..<reserved>
3437
+
FB13..FB17 ; DISALLOWED # ARMENIAN SMALL LIGATURE MEN NOW..ARMENIAN SM
3438
+
FB18..FB1C ; UNASSIGNED # <reserved>..<reserved>
3439
+
FB1D ; DISALLOWED # HEBREW LETTER YOD WITH HIRIQ
3440
+
FB1E ; PVALID # HEBREW POINT JUDEO-SPANISH VARIKA
3441
+
FB1F..FB36 ; DISALLOWED # HEBREW LIGATURE YIDDISH YOD YOD PATAH..HEBRE
3442
+
FB37 ; UNASSIGNED # <reserved>
3443
+
FB38..FB3C ; DISALLOWED # HEBREW LETTER TET WITH DAGESH..HEBREW LETTER
3444
+
FB3D ; UNASSIGNED # <reserved>
3445
+
FB3E ; DISALLOWED # HEBREW LETTER MEM WITH DAGESH
3446
+
FB3F ; UNASSIGNED # <reserved>
3447
+
FB40..FB41 ; DISALLOWED # HEBREW LETTER NUN WITH DAGESH..HEBREW LETTER
3448
+
FB42 ; UNASSIGNED # <reserved>
3449
+
FB43..FB44 ; DISALLOWED # HEBREW LETTER FINAL PE WITH DAGESH..HEBREW L
3450
+
FB45 ; UNASSIGNED # <reserved>
3451
+
FB46..FBB1 ; DISALLOWED # HEBREW LETTER TSADI WITH DAGESH..ARABIC LETT
3452
+
FBB2..FBD2 ; UNASSIGNED # <reserved>..<reserved>
3453
+
FBD3..FD3F ; DISALLOWED # ARABIC LETTER NG ISOLATED FORM..ORNATE RIGHT
3454
+
FD40..FD4F ; UNASSIGNED # <reserved>..<reserved>
3455
+
FD50..FD8F ; DISALLOWED # ARABIC LIGATURE TEH WITH JEEM WITH MEEM INIT
3456
+
FD90..FD91 ; UNASSIGNED # <reserved>..<reserved>
3457
+
FD92..FDC7 ; DISALLOWED # ARABIC LIGATURE MEEM WITH JEEM WITH KHAH INI
3458
+
FDC8..FDCF ; UNASSIGNED # <reserved>..<reserved>
3459
+
FDD0..FDFD ; DISALLOWED # <noncharacter>..ARABIC LIGATURE BISMILLAH AR
3460
+
FDFE..FDFF ; UNASSIGNED # <reserved>..<reserved>
3461
+
FE00..FE19 ; DISALLOWED # VARIATION SELECTOR-1..PRESENTATION FORM FOR
3462
+
FE1A..FE1F ; UNASSIGNED # <reserved>..<reserved>
3463
+
FE20..FE26 ; PVALID # COMBINING LIGATURE LEFT HALF..COMBINING CONJ
3464
+
FE27..FE2F ; UNASSIGNED # <reserved>..<reserved>
3465
+
FE30..FE52 ; DISALLOWED # PRESENTATION FORM FOR VERTICAL TWO DOT LEADE
3466
+
FE53 ; UNASSIGNED # <reserved>
3467
+
FE54..FE66 ; DISALLOWED # SMALL SEMICOLON..SMALL EQUALS SIGN
3468
+
FE67 ; UNASSIGNED # <reserved>
3469
+
FE68..FE6B ; DISALLOWED # SMALL REVERSE SOLIDUS..SMALL COMMERCIAL AT
3470
+
FE6C..FE6F ; UNASSIGNED # <reserved>..<reserved>
3471
+
3472
+
3473
+
3474
+
Faltstrom Standards Track [Page 62]
3475
+
3476
+
RFC 5892 IDNA Code Points August 2010
3477
+
3478
+
3479
+
FE70..FE72 ; DISALLOWED # ARABIC FATHATAN ISOLATED FORM..ARABIC DAMMAT
3480
+
FE73 ; PVALID # ARABIC TAIL FRAGMENT
3481
+
FE74 ; DISALLOWED # ARABIC KASRATAN ISOLATED FORM
3482
+
FE75 ; UNASSIGNED # <reserved>
3483
+
FE76..FEFC ; DISALLOWED # ARABIC FATHA ISOLATED FORM..ARABIC LIGATURE
3484
+
FEFD..FEFE ; UNASSIGNED # <reserved>..<reserved>
3485
+
FEFF ; DISALLOWED # ZERO WIDTH NO-BREAK SPACE
3486
+
FF00 ; UNASSIGNED # <reserved>
3487
+
FF01..FFBE ; DISALLOWED # FULLWIDTH EXCLAMATION MARK..HALFWIDTH HANGUL
3488
+
FFBF..FFC1 ; UNASSIGNED # <reserved>..<reserved>
3489
+
FFC2..FFC7 ; DISALLOWED # HALFWIDTH HANGUL LETTER A..HALFWIDTH HANGUL
3490
+
FFC8..FFC9 ; UNASSIGNED # <reserved>..<reserved>
3491
+
FFCA..FFCF ; DISALLOWED # HALFWIDTH HANGUL LETTER YEO..HALFWIDTH HANGU
3492
+
FFD0..FFD1 ; UNASSIGNED # <reserved>..<reserved>
3493
+
FFD2..FFD7 ; DISALLOWED # HALFWIDTH HANGUL LETTER YO..HALFWIDTH HANGUL
3494
+
FFD8..FFD9 ; UNASSIGNED # <reserved>..<reserved>
3495
+
FFDA..FFDC ; DISALLOWED # HALFWIDTH HANGUL LETTER EU..HALFWIDTH HANGUL
3496
+
FFDD..FFDF ; UNASSIGNED # <reserved>..<reserved>
3497
+
FFE0..FFE6 ; DISALLOWED # FULLWIDTH CENT SIGN..FULLWIDTH WON SIGN
3498
+
FFE7 ; UNASSIGNED # <reserved>
3499
+
FFE8..FFEE ; DISALLOWED # HALFWIDTH FORMS LIGHT VERTICAL..HALFWIDTH WH
3500
+
FFEF..FFF8 ; UNASSIGNED # <reserved>..<reserved>
3501
+
FFF9..FFFF ; DISALLOWED # INTERLINEAR ANNOTATION ANCHOR..<noncharacter
3502
+
10000..1000B; PVALID # LINEAR B SYLLABLE B008 A..LINEAR B SYLLABLE
3503
+
1000C ; UNASSIGNED # <reserved>
3504
+
1000D..10026; PVALID # LINEAR B SYLLABLE B036 JO..LINEAR B SYLLABLE
3505
+
10027 ; UNASSIGNED # <reserved>
3506
+
10028..1003A; PVALID # LINEAR B SYLLABLE B060 RA..LINEAR B SYLLABLE
3507
+
1003B ; UNASSIGNED # <reserved>
3508
+
1003C..1003D; PVALID # LINEAR B SYLLABLE B017 ZA..LINEAR B SYLLABLE
3509
+
1003E ; UNASSIGNED # <reserved>
3510
+
1003F..1004D; PVALID # LINEAR B SYLLABLE B020 ZO..LINEAR B SYLLABLE
3511
+
1004E..1004F; UNASSIGNED # <reserved>..<reserved>
3512
+
10050..1005D; PVALID # LINEAR B SYMBOL B018..LINEAR B SYMBOL B089
3513
+
1005E..1007F; UNASSIGNED # <reserved>..<reserved>
3514
+
10080..100FA; PVALID # LINEAR B IDEOGRAM B100 MAN..LINEAR B IDEOGRA
3515
+
100FB..100FF; UNASSIGNED # <reserved>..<reserved>
3516
+
10100..10102; DISALLOWED # AEGEAN WORD SEPARATOR LINE..AEGEAN CHECK MAR
3517
+
10103..10106; UNASSIGNED # <reserved>..<reserved>
3518
+
10107..10133; DISALLOWED # AEGEAN NUMBER ONE..AEGEAN NUMBER NINETY THOU
3519
+
10134..10136; UNASSIGNED # <reserved>..<reserved>
3520
+
10137..1018A; DISALLOWED # AEGEAN WEIGHT BASE UNIT..GREEK ZERO SIGN
3521
+
1018B..1018F; UNASSIGNED # <reserved>..<reserved>
3522
+
10190..1019B; DISALLOWED # ROMAN SEXTANS SIGN..ROMAN CENTURIAL SIGN
3523
+
1019C..101CF; UNASSIGNED # <reserved>..<reserved>
3524
+
101D0..101FC; DISALLOWED # PHAISTOS DISC SIGN PEDESTRIAN..PHAISTOS DISC
3525
+
101FD ; PVALID # PHAISTOS DISC SIGN COMBINING OBLIQUE STROKE
3526
+
101FE..1027F; UNASSIGNED # <reserved>..<reserved>
3527
+
3528
+
3529
+
3530
+
Faltstrom Standards Track [Page 63]
3531
+
3532
+
RFC 5892 IDNA Code Points August 2010
3533
+
3534
+
3535
+
10280..1029C; PVALID # LYCIAN LETTER A..LYCIAN LETTER X
3536
+
1029D..1029F; UNASSIGNED # <reserved>..<reserved>
3537
+
102A0..102D0; PVALID # CARIAN LETTER A..CARIAN LETTER UUU3
3538
+
102D1..102FF; UNASSIGNED # <reserved>..<reserved>
3539
+
10300..1031E; PVALID # OLD ITALIC LETTER A..OLD ITALIC LETTER UU
3540
+
1031F ; UNASSIGNED # <reserved>
3541
+
10320..10323; DISALLOWED # OLD ITALIC NUMERAL ONE..OLD ITALIC NUMERAL F
3542
+
10324..1032F; UNASSIGNED # <reserved>..<reserved>
3543
+
10330..10340; PVALID # GOTHIC LETTER AHSA..GOTHIC LETTER PAIRTHRA
3544
+
10341 ; DISALLOWED # GOTHIC LETTER NINETY
3545
+
10342..10349; PVALID # GOTHIC LETTER RAIDA..GOTHIC LETTER OTHAL
3546
+
1034A ; DISALLOWED # GOTHIC LETTER NINE HUNDRED
3547
+
1034B..1037F; UNASSIGNED # <reserved>..<reserved>
3548
+
10380..1039D; PVALID # UGARITIC LETTER ALPA..UGARITIC LETTER SSU
3549
+
1039E ; UNASSIGNED # <reserved>
3550
+
1039F ; DISALLOWED # UGARITIC WORD DIVIDER
3551
+
103A0..103C3; PVALID # OLD PERSIAN SIGN A..OLD PERSIAN SIGN HA
3552
+
103C4..103C7; UNASSIGNED # <reserved>..<reserved>
3553
+
103C8..103CF; PVALID # OLD PERSIAN SIGN AURAMAZDAA..OLD PERSIAN SIG
3554
+
103D0..103D5; DISALLOWED # OLD PERSIAN WORD DIVIDER..OLD PERSIAN NUMBER
3555
+
103D6..103FF; UNASSIGNED # <reserved>..<reserved>
3556
+
10400..10427; DISALLOWED # DESERET CAPITAL LETTER LONG I..DESERET CAPIT
3557
+
10428..1049D; PVALID # DESERET SMALL LETTER LONG I..OSMANYA LETTER
3558
+
1049E..1049F; UNASSIGNED # <reserved>..<reserved>
3559
+
104A0..104A9; PVALID # OSMANYA DIGIT ZERO..OSMANYA DIGIT NINE
3560
+
104AA..107FF; UNASSIGNED # <reserved>..<reserved>
3561
+
10800..10805; PVALID # CYPRIOT SYLLABLE A..CYPRIOT SYLLABLE JA
3562
+
10806..10807; UNASSIGNED # <reserved>..<reserved>
3563
+
10808 ; PVALID # CYPRIOT SYLLABLE JO
3564
+
10809 ; UNASSIGNED # <reserved>
3565
+
1080A..10835; PVALID # CYPRIOT SYLLABLE KA..CYPRIOT SYLLABLE WO
3566
+
10836 ; UNASSIGNED # <reserved>
3567
+
10837..10838; PVALID # CYPRIOT SYLLABLE XA..CYPRIOT SYLLABLE XE
3568
+
10839..1083B; UNASSIGNED # <reserved>..<reserved>
3569
+
1083C ; PVALID # CYPRIOT SYLLABLE ZA
3570
+
1083D..1083E; UNASSIGNED # <reserved>..<reserved>
3571
+
1083F..10855; PVALID # CYPRIOT SYLLABLE ZO..IMPERIAL ARAMAIC LETTER
3572
+
10856 ; UNASSIGNED # <reserved>
3573
+
10857..1085F; DISALLOWED # IMPERIAL ARAMAIC SECTION SIGN..IMPERIAL ARAM
3574
+
10860..108FF; UNASSIGNED # <reserved>..<reserved>
3575
+
10900..10915; PVALID # PHOENICIAN LETTER ALF..PHOENICIAN LETTER TAU
3576
+
10916..1091B; DISALLOWED # PHOENICIAN NUMBER ONE..PHOENICIAN NUMBER THR
3577
+
1091C..1091E; UNASSIGNED # <reserved>..<reserved>
3578
+
1091F ; DISALLOWED # PHOENICIAN WORD SEPARATOR
3579
+
10920..10939; PVALID # LYDIAN LETTER A..LYDIAN LETTER C
3580
+
1093A..1093E; UNASSIGNED # <reserved>..<reserved>
3581
+
1093F ; DISALLOWED # LYDIAN TRIANGULAR MARK
3582
+
10940..109FF; UNASSIGNED # <reserved>..<reserved>
3583
+
3584
+
3585
+
3586
+
Faltstrom Standards Track [Page 64]
3587
+
3588
+
RFC 5892 IDNA Code Points August 2010
3589
+
3590
+
3591
+
10A00..10A03; PVALID # KHAROSHTHI LETTER A..KHAROSHTHI VOWEL SIGN V
3592
+
10A04 ; UNASSIGNED # <reserved>
3593
+
10A05..10A06; PVALID # KHAROSHTHI VOWEL SIGN E..KHAROSHTHI VOWEL SI
3594
+
10A07..10A0B; UNASSIGNED # <reserved>..<reserved>
3595
+
10A0C..10A13; PVALID # KHAROSHTHI VOWEL LENGTH MARK..KHAROSHTHI LET
3596
+
10A14 ; UNASSIGNED # <reserved>
3597
+
10A15..10A17; PVALID # KHAROSHTHI LETTER CA..KHAROSHTHI LETTER JA
3598
+
10A18 ; UNASSIGNED # <reserved>
3599
+
10A19..10A33; PVALID # KHAROSHTHI LETTER NYA..KHAROSHTHI LETTER TTT
3600
+
10A34..10A37; UNASSIGNED # <reserved>..<reserved>
3601
+
10A38..10A3A; PVALID # KHAROSHTHI SIGN BAR ABOVE..KHAROSHTHI SIGN D
3602
+
10A3B..10A3E; UNASSIGNED # <reserved>..<reserved>
3603
+
10A3F ; PVALID # KHAROSHTHI VIRAMA
3604
+
10A40..10A47; DISALLOWED # KHAROSHTHI DIGIT ONE..KHAROSHTHI NUMBER ONE
3605
+
10A48..10A4F; UNASSIGNED # <reserved>..<reserved>
3606
+
10A50..10A58; DISALLOWED # KHAROSHTHI PUNCTUATION DOT..KHAROSHTHI PUNCT
3607
+
10A59..10A5F; UNASSIGNED # <reserved>..<reserved>
3608
+
10A60..10A7C; PVALID # OLD SOUTH ARABIAN LETTER HE..OLD SOUTH ARABI
3609
+
10A7D..10A7F; DISALLOWED # OLD SOUTH ARABIAN NUMBER ONE..OLD SOUTH ARAB
3610
+
10A80..10AFF; UNASSIGNED # <reserved>..<reserved>
3611
+
10B00..10B35; PVALID # AVESTAN LETTER A..AVESTAN LETTER HE
3612
+
10B36..10B38; UNASSIGNED # <reserved>..<reserved>
3613
+
10B39..10B3F; DISALLOWED # AVESTAN ABBREVIATION MARK..LARGE ONE RING OV
3614
+
10B40..10B55; PVALID # INSCRIPTIONAL PARTHIAN LETTER ALEPH..INSCRIP
3615
+
10B56..10B57; UNASSIGNED # <reserved>..<reserved>
3616
+
10B58..10B5F; DISALLOWED # INSCRIPTIONAL PARTHIAN NUMBER ONE..INSCRIPTI
3617
+
10B60..10B72; PVALID # INSCRIPTIONAL PAHLAVI LETTER ALEPH..INSCRIPT
3618
+
10B73..10B77; UNASSIGNED # <reserved>..<reserved>
3619
+
10B78..10B7F; DISALLOWED # INSCRIPTIONAL PAHLAVI NUMBER ONE..INSCRIPTIO
3620
+
10B80..10BFF; UNASSIGNED # <reserved>..<reserved>
3621
+
10C00..10C48; PVALID # OLD TURKIC LETTER ORKHON A..OLD TURKIC LETTE
3622
+
10C49..10E5F; UNASSIGNED # <reserved>..<reserved>
3623
+
10E60..10E7E; DISALLOWED # RUMI DIGIT ONE..RUMI FRACTION TWO THIRDS
3624
+
10E7F..1107F; UNASSIGNED # <reserved>..<reserved>
3625
+
11080..110BA; PVALID # KAITHI SIGN CANDRABINDU..KAITHI SIGN NUKTA
3626
+
110BB..110C1; DISALLOWED # KAITHI ABBREVIATION SIGN..KAITHI DOUBLE DAND
3627
+
110C2..11FFF; UNASSIGNED # <reserved>..<reserved>
3628
+
12000..1236E; PVALID # CUNEIFORM SIGN A..CUNEIFORM SIGN ZUM
3629
+
1236F..123FF; UNASSIGNED # <reserved>..<reserved>
3630
+
12400..12462; DISALLOWED # CUNEIFORM NUMERIC SIGN TWO ASH..CUNEIFORM NU
3631
+
12463..1246F; UNASSIGNED # <reserved>..<reserved>
3632
+
12470..12473; DISALLOWED # CUNEIFORM PUNCTUATION SIGN OLD ASSYRIAN WORD
3633
+
12474..12FFF; UNASSIGNED # <reserved>..<reserved>
3634
+
13000..1342E; PVALID # EGYPTIAN HIEROGLYPH A001..EGYPTIAN HIEROGLYP
3635
+
1342F..1CFFF; UNASSIGNED # <reserved>..<reserved>
3636
+
1D000..1D0F5; DISALLOWED # BYZANTINE MUSICAL SYMBOL PSILI..BYZANTINE MU
3637
+
1D0F6..1D0FF; UNASSIGNED # <reserved>..<reserved>
3638
+
1D100..1D126; DISALLOWED # MUSICAL SYMBOL SINGLE BARLINE..MUSICAL SYMBO
3639
+
3640
+
3641
+
3642
+
Faltstrom Standards Track [Page 65]
3643
+
3644
+
RFC 5892 IDNA Code Points August 2010
3645
+
3646
+
3647
+
1D127..1D128; UNASSIGNED # <reserved>..<reserved>
3648
+
1D129..1D1DD; DISALLOWED # MUSICAL SYMBOL MULTIPLE MEASURE REST..MUSICA
3649
+
1D1DE..1D1FF; UNASSIGNED # <reserved>..<reserved>
3650
+
1D200..1D245; DISALLOWED # GREEK VOCAL NOTATION SYMBOL-1..GREEK MUSICAL
3651
+
1D246..1D2FF; UNASSIGNED # <reserved>..<reserved>
3652
+
1D300..1D356; DISALLOWED # MONOGRAM FOR EARTH..TETRAGRAM FOR FOSTERING
3653
+
1D357..1D35F; UNASSIGNED # <reserved>..<reserved>
3654
+
1D360..1D371; DISALLOWED # COUNTING ROD UNIT DIGIT ONE..COUNTING ROD TE
3655
+
1D372..1D3FF; UNASSIGNED # <reserved>..<reserved>
3656
+
1D400..1D454; DISALLOWED # MATHEMATICAL BOLD CAPITAL A..MATHEMATICAL IT
3657
+
1D455 ; UNASSIGNED # <reserved>
3658
+
1D456..1D49C; DISALLOWED # MATHEMATICAL ITALIC SMALL I..MATHEMATICAL SC
3659
+
1D49D ; UNASSIGNED # <reserved>
3660
+
1D49E..1D49F; DISALLOWED # MATHEMATICAL SCRIPT CAPITAL C..MATHEMATICAL
3661
+
1D4A0..1D4A1; UNASSIGNED # <reserved>..<reserved>
3662
+
1D4A2 ; DISALLOWED # MATHEMATICAL SCRIPT CAPITAL G
3663
+
1D4A3..1D4A4; UNASSIGNED # <reserved>..<reserved>
3664
+
1D4A5..1D4A6; DISALLOWED # MATHEMATICAL SCRIPT CAPITAL J..MATHEMATICAL
3665
+
1D4A7..1D4A8; UNASSIGNED # <reserved>..<reserved>
3666
+
1D4A9..1D4AC; DISALLOWED # MATHEMATICAL SCRIPT CAPITAL N..MATHEMATICAL
3667
+
1D4AD ; UNASSIGNED # <reserved>
3668
+
1D4AE..1D4B9; DISALLOWED # MATHEMATICAL SCRIPT CAPITAL S..MATHEMATICAL
3669
+
1D4BA ; UNASSIGNED # <reserved>
3670
+
1D4BB ; DISALLOWED # MATHEMATICAL SCRIPT SMALL F
3671
+
1D4BC ; UNASSIGNED # <reserved>
3672
+
1D4BD..1D4C3; DISALLOWED # MATHEMATICAL SCRIPT SMALL H..MATHEMATICAL SC
3673
+
1D4C4 ; UNASSIGNED # <reserved>
3674
+
1D4C5..1D505; DISALLOWED # MATHEMATICAL SCRIPT SMALL P..MATHEMATICAL FR
3675
+
1D506 ; UNASSIGNED # <reserved>
3676
+
1D507..1D50A; DISALLOWED # MATHEMATICAL FRAKTUR CAPITAL D..MATHEMATICAL
3677
+
1D50B..1D50C; UNASSIGNED # <reserved>..<reserved>
3678
+
1D50D..1D514; DISALLOWED # MATHEMATICAL FRAKTUR CAPITAL J..MATHEMATICAL
3679
+
1D515 ; UNASSIGNED # <reserved>
3680
+
1D516..1D51C; DISALLOWED # MATHEMATICAL FRAKTUR CAPITAL S..MATHEMATICAL
3681
+
1D51D ; UNASSIGNED # <reserved>
3682
+
1D51E..1D539; DISALLOWED # MATHEMATICAL FRAKTUR SMALL A..MATHEMATICAL D
3683
+
1D53A ; UNASSIGNED # <reserved>
3684
+
1D53B..1D53E; DISALLOWED # MATHEMATICAL DOUBLE-STRUCK CAPITAL D..MATHEM
3685
+
1D53F ; UNASSIGNED # <reserved>
3686
+
1D540..1D544; DISALLOWED # MATHEMATICAL DOUBLE-STRUCK CAPITAL I..MATHEM
3687
+
1D545 ; UNASSIGNED # <reserved>
3688
+
1D546 ; DISALLOWED # MATHEMATICAL DOUBLE-STRUCK CAPITAL O
3689
+
1D547..1D549; UNASSIGNED # <reserved>..<reserved>
3690
+
1D54A..1D550; DISALLOWED # MATHEMATICAL DOUBLE-STRUCK CAPITAL S..MATHEM
3691
+
1D551 ; UNASSIGNED # <reserved>
3692
+
1D552..1D6A5; DISALLOWED # MATHEMATICAL DOUBLE-STRUCK SMALL A..MATHEMAT
3693
+
1D6A6..1D6A7; UNASSIGNED # <reserved>..<reserved>
3694
+
1D6A8..1D7CB; DISALLOWED # MATHEMATICAL BOLD CAPITAL ALPHA..MATHEMATICA
3695
+
3696
+
3697
+
3698
+
Faltstrom Standards Track [Page 66]
3699
+
3700
+
RFC 5892 IDNA Code Points August 2010
3701
+
3702
+
3703
+
1D7CC..1D7CD; UNASSIGNED # <reserved>..<reserved>
3704
+
1D7CE..1D7FF; DISALLOWED # MATHEMATICAL BOLD DIGIT ZERO..MATHEMATICAL M
3705
+
1D800..1EFFF; UNASSIGNED # <reserved>..<reserved>
3706
+
1F000..1F02B; DISALLOWED # MAHJONG TILE EAST WIND..MAHJONG TILE BACK
3707
+
1F02C..1F02F; UNASSIGNED # <reserved>..<reserved>
3708
+
1F030..1F093; DISALLOWED # DOMINO TILE HORIZONTAL BACK..DOMINO TILE VER
3709
+
1F094..1F0FF; UNASSIGNED # <reserved>..<reserved>
3710
+
1F100..1F10A; DISALLOWED # DIGIT ZERO FULL STOP..DIGIT NINE COMMA
3711
+
1F10B..1F10F; UNASSIGNED # <reserved>..<reserved>
3712
+
1F110..1F12E; DISALLOWED # PARENTHESIZED LATIN CAPITAL LETTER A..CIRCLE
3713
+
1F12F..1F130; UNASSIGNED # <reserved>..<reserved>
3714
+
1F131 ; DISALLOWED # SQUARED LATIN CAPITAL LETTER B
3715
+
1F132..1F13C; UNASSIGNED # <reserved>..<reserved>
3716
+
1F13D ; DISALLOWED # SQUARED LATIN CAPITAL LETTER N
3717
+
1F13E ; UNASSIGNED # <reserved>
3718
+
1F13F ; DISALLOWED # SQUARED LATIN CAPITAL LETTER P
3719
+
1F140..1F141; UNASSIGNED # <reserved>..<reserved>
3720
+
1F142 ; DISALLOWED # SQUARED LATIN CAPITAL LETTER S
3721
+
1F143..1F145; UNASSIGNED # <reserved>..<reserved>
3722
+
1F146 ; DISALLOWED # SQUARED LATIN CAPITAL LETTER W
3723
+
1F147..1F149; UNASSIGNED # <reserved>..<reserved>
3724
+
1F14A..1F14E; DISALLOWED # SQUARED HV..SQUARED PPV
3725
+
1F14F..1F156; UNASSIGNED # <reserved>..<reserved>
3726
+
1F157 ; DISALLOWED # NEGATIVE CIRCLED LATIN CAPITAL LETTER H
3727
+
1F158..1F15E; UNASSIGNED # <reserved>..<reserved>
3728
+
1F15F ; DISALLOWED # NEGATIVE CIRCLED LATIN CAPITAL LETTER P
3729
+
1F160..1F178; UNASSIGNED # <reserved>..<reserved>
3730
+
1F179 ; DISALLOWED # NEGATIVE SQUARED LATIN CAPITAL LETTER J
3731
+
1F17A ; UNASSIGNED # <reserved>
3732
+
1F17B..1F17C; DISALLOWED # NEGATIVE SQUARED LATIN CAPITAL LETTER L..NEG
3733
+
1F17D..1F17E; UNASSIGNED # <reserved>..<reserved>
3734
+
1F17F ; DISALLOWED # NEGATIVE SQUARED LATIN CAPITAL LETTER P
3735
+
1F180..1F189; UNASSIGNED # <reserved>..<reserved>
3736
+
1F18A..1F18D; DISALLOWED # CROSSED NEGATIVE SQUARED LATIN CAPITAL LETTE
3737
+
1F18E..1F18F; UNASSIGNED # <reserved>..<reserved>
3738
+
1F190 ; DISALLOWED # SQUARE DJ
3739
+
1F191..1F1FF; UNASSIGNED # <reserved>..<reserved>
3740
+
1F200 ; DISALLOWED # SQUARE HIRAGANA HOKA
3741
+
1F201..1F20F; UNASSIGNED # <reserved>..<reserved>
3742
+
1F210..1F231; DISALLOWED # SQUARED CJK UNIFIED IDEOGRAPH-624B..SQUARED
3743
+
1F232..1F23F; UNASSIGNED # <reserved>..<reserved>
3744
+
1F240..1F248; DISALLOWED # TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRA
3745
+
1F249..1FFFD; UNASSIGNED # <reserved>..<reserved>
3746
+
1FFFE..1FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3747
+
20000..2A6D6; PVALID # <CJK Ideograph Extension B>..<CJK Ideograph
3748
+
2A6D7..2A6FF; UNASSIGNED # <reserved>..<reserved>
3749
+
2A700..2B734; PVALID # <CJK Ideograph Extension C>..<CJK Ideograph
3750
+
2B735..2F7FF; UNASSIGNED # <reserved>..<reserved>
3751
+
3752
+
3753
+
3754
+
Faltstrom Standards Track [Page 67]
3755
+
3756
+
RFC 5892 IDNA Code Points August 2010
3757
+
3758
+
3759
+
2F800..2FA1D; DISALLOWED # CJK COMPATIBILITY IDEOGRAPH-2F800..CJK COMPA
3760
+
2FA1E..2FFFD; UNASSIGNED # <reserved>..<reserved>
3761
+
2FFFE..2FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3762
+
30000..3FFFD; UNASSIGNED # <reserved>..<reserved>
3763
+
3FFFE..3FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3764
+
40000..4FFFD; UNASSIGNED # <reserved>..<reserved>
3765
+
4FFFE..4FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3766
+
50000..5FFFD; UNASSIGNED # <reserved>..<reserved>
3767
+
5FFFE..5FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3768
+
60000..6FFFD; UNASSIGNED # <reserved>..<reserved>
3769
+
6FFFE..6FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3770
+
70000..7FFFD; UNASSIGNED # <reserved>..<reserved>
3771
+
7FFFE..7FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3772
+
80000..8FFFD; UNASSIGNED # <reserved>..<reserved>
3773
+
8FFFE..8FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3774
+
90000..9FFFD; UNASSIGNED # <reserved>..<reserved>
3775
+
9FFFE..9FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3776
+
A0000..AFFFD; UNASSIGNED # <reserved>..<reserved>
3777
+
AFFFE..AFFFF; DISALLOWED # <noncharacter>..<noncharacter>
3778
+
B0000..BFFFD; UNASSIGNED # <reserved>..<reserved>
3779
+
BFFFE..BFFFF; DISALLOWED # <noncharacter>..<noncharacter>
3780
+
C0000..CFFFD; UNASSIGNED # <reserved>..<reserved>
3781
+
CFFFE..CFFFF; DISALLOWED # <noncharacter>..<noncharacter>
3782
+
D0000..DFFFD; UNASSIGNED # <reserved>..<reserved>
3783
+
DFFFE..DFFFF; DISALLOWED # <noncharacter>..<noncharacter>
3784
+
E0000 ; UNASSIGNED # <reserved>
3785
+
E0001 ; DISALLOWED # LANGUAGE TAG
3786
+
E0002..E001F; UNASSIGNED # <reserved>..<reserved>
3787
+
E0020..E007F; DISALLOWED # TAG SPACE..CANCEL TAG
3788
+
E0080..E00FF; UNASSIGNED # <reserved>..<reserved>
3789
+
E0100..E01EF; DISALLOWED # VARIATION SELECTOR-17..VARIATION SELECTOR-25
3790
+
E01F0..EFFFD; UNASSIGNED # <reserved>..<reserved>
3791
+
EFFFE..10FFFF; DISALLOWED # <noncharacter>..<noncharacter>
3792
+
3793
+
3794
+
3795
+
3796
+
3797
+
3798
+
3799
+
3800
+
3801
+
3802
+
3803
+
3804
+
3805
+
3806
+
3807
+
3808
+
3809
+
3810
+
Faltstrom Standards Track [Page 68]
3811
+
3812
+
RFC 5892 IDNA Code Points August 2010
3813
+
3814
+
3815
+
8. References
3816
+
3817
+
8.1. Normative References
3818
+
3819
+
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
3820
+
Requirement Levels", BCP 14, RFC 2119, March 1997.
3821
+
3822
+
[TR15] Davis, M. and M. Duerst, "Unicode Standard Annex #15,
3823
+
Unicode Normalization Forms, an integral part of the
3824
+
Unicode Standard",
3825
+
<http://unicode.org/unicode/reports/tr15/>.
3826
+
3827
+
[Unicode] The Unicode Consortium, "The Unicode Standard, Version
3828
+
5.0", 2007. Boston, MA, USA: Addison-Wesley. ISBN
3829
+
0-321-48091-0. This printed reference has now been
3830
+
updated online to reflect additional code points. For
3831
+
code points, the reference at the time this document was
3832
+
published is to Unicode 5.2.
3833
+
3834
+
[Unicode52] The Unicode Consortium. The Unicode Standard, Version
3835
+
5.2.0, defined by: "The Unicode Standard, Version
3836
+
5.2.0", (Mountain View, CA: The Unicode Consortium,
3837
+
2009. ISBN 978-1-936213-00-9).
3838
+
<http://www.unicode.org/versions/Unicode5.2.0/>.
3839
+
3840
+
8.2. Informative References
3841
+
3842
+
[BlockNames] "Blocks-5.2.0.txt", Unicode Character Database,
3843
+
May 2009,
3844
+
<http://unicode.org/Public/5.2.0/ucd/Blocks.txt>.
3845
+
3846
+
[DerivedCoreProperties]
3847
+
"DerivedCoreProperties-5.2.0.txt", Unicode Character
3848
+
Database, August 2009, <http://unicode.org/Public/5.2.0/
3849
+
ucd/DerivedCoreProperties.txt>.
3850
+
3851
+
[RFC3454] Hoffman, P. and M. Blanchet, "Preparation of
3852
+
Internationalized Strings ("stringprep")", RFC 3454,
3853
+
December 2002.
3854
+
3855
+
[RFC3491] Hoffman, P. and M. Blanchet, "Nameprep: A Stringprep
3856
+
Profile for Internationalized Domain Names (IDN)",
3857
+
RFC 3491, March 2003.
3858
+
3859
+
[RFC4690] Klensin, J., Faltstrom, P., Karp, C., and IAB, "Review
3860
+
and Recommendations for Internationalized Domain Names
3861
+
(IDNs)", RFC 4690, September 2006.
3862
+
3863
+
3864
+
3865
+
3866
+
Faltstrom Standards Track [Page 69]
3867
+
3868
+
RFC 5892 IDNA Code Points August 2010
3869
+
3870
+
3871
+
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
3872
+
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
3873
+
May 2008.
3874
+
3875
+
[RFC5890] Klensin, J., "Internationalized Domain Names for
3876
+
Applications (IDNA): Definitions and Document
3877
+
Framework", RFC 5890, August 2010.
3878
+
3879
+
[RFC5891] Klensin, J., "Internationalized Domain Names in
3880
+
Applications (IDNA): Protocol", RFC 5891, August 2010.
3881
+
3882
+
[RFC5893] Alvestrand, H., Ed. and C. Karp, "Right-to-Left Scripts
3883
+
for Internationalized Domain Names for Applications
3884
+
(IDNA)", RFC 5893, August 2010.
3885
+
3886
+
[RFC5894] Klensin, J., "Internationalized Domain Names for
3887
+
Applications (IDNA): Background, Explanation, and
3888
+
Rationale", RFC 5894, August 2010.
3889
+
3890
+
Author's Address
3891
+
3892
+
Patrik Faltstrom (editor)
3893
+
Cisco
3894
+
3895
+
EMail: paf@cisco.com
3896
+
3897
+
3898
+
3899
+
3900
+
3901
+
3902
+
3903
+
3904
+
3905
+
3906
+
3907
+
3908
+
3909
+
3910
+
3911
+
3912
+
3913
+
3914
+
3915
+
3916
+
3917
+
3918
+
3919
+
3920
+
3921
+
3922
+
Faltstrom Standards Track [Page 70]
3923
+
+955
spec/rfc5893.txt
+955
spec/rfc5893.txt
···
1
+
2
+
3
+
4
+
5
+
6
+
7
+
Internet Engineering Task Force (IETF) H. Alvestrand, Ed.
8
+
Request for Comments: 5893 Google
9
+
Category: Standards Track C. Karp
10
+
ISSN: 2070-1721 Swedish Museum of Natural History
11
+
August 2010
12
+
13
+
14
+
Right-to-Left Scripts for
15
+
Internationalized Domain Names for Applications (IDNA)
16
+
17
+
Abstract
18
+
19
+
The use of right-to-left scripts in Internationalized Domain Names
20
+
(IDNs) has presented several challenges. This memo provides a new
21
+
Bidi rule for Internationalized Domain Names for Applications (IDNA)
22
+
labels, based on the encountered problems with some scripts and some
23
+
shortcomings in the 2003 IDNA Bidi criterion.
24
+
25
+
Status of This Memo
26
+
27
+
This is an Internet Standards Track document.
28
+
29
+
This document is a product of the Internet Engineering Task Force
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(IETF). It represents the consensus of the IETF community. It has
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received public review and has been approved for publication by the
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Internet Engineering Steering Group (IESG). Further information on
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Internet Standards is available in Section 2 of RFC 5741.
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+
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Information about the current status of this document, any errata,
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and how to provide feedback on it may be obtained at
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http://www.rfc-editor.org/info/rfc5893.
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Copyright Notice
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Copyright (c) 2010 IETF Trust and the persons identified as the
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document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
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+
Provisions Relating to IETF Documents
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(http://trustee.ietf.org/license-info) in effect on the date of
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+
publication of this document. Please review these documents
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+
carefully, as they describe your rights and restrictions with respect
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+
to this document. Code Components extracted from this document must
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+
include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
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described in the Simplified BSD License.
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Alvestrand & Karp Standards Track [Page 1]
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RFC 5893 IDNA Right to Left August 2010
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Table of Contents
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
66
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1.1. Purpose and Applicability . . . . . . . . . . . . . . . . 2
67
+
1.2. Background and History . . . . . . . . . . . . . . . . . . 3
68
+
1.3. Structure of the Rest of This Document . . . . . . . . . . 3
69
+
1.4. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
70
+
2. The Bidi Rule . . . . . . . . . . . . . . . . . . . . . . . . 6
71
+
3. The Requirement Set for the Bidi Rule . . . . . . . . . . . . 6
72
+
4. Examples of Issues Found with RFC 3454 . . . . . . . . . . . . 9
73
+
4.1. Dhivehi . . . . . . . . . . . . . . . . . . . . . . . . . 9
74
+
4.2. Yiddish . . . . . . . . . . . . . . . . . . . . . . . . . 10
75
+
4.3. Strings with Numbers . . . . . . . . . . . . . . . . . . . 12
76
+
5. Troublesome Situations and Guidelines . . . . . . . . . . . . 12
77
+
6. Other Issues in Need of Resolution . . . . . . . . . . . . . . 13
78
+
7. Compatibility Considerations . . . . . . . . . . . . . . . . . 14
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+
7.1. Backwards Compatibility Considerations . . . . . . . . . . 14
80
+
7.2. Forward Compatibility Considerations . . . . . . . . . . . 15
81
+
8. Security Considerations . . . . . . . . . . . . . . . . . . . 15
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9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
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+
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
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10.1. Normative References . . . . . . . . . . . . . . . . . . . 16
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+
10.2. Informative References . . . . . . . . . . . . . . . . . . 17
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+
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1. Introduction
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+
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1.1. Purpose and Applicability
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+
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The purpose of this document is to establish a rule that can be
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applied to Internationalized Domain Name (IDN) labels in Unicode form
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+
(U-labels) containing characters from scripts that are written from
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right to left. It is part of the revised IDNA protocol [RFC5891].
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When labels satisfy the rule, and when certain other conditions are
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satisfied, there is only a minimal chance of these labels being
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displayed in a confusing way by the Unicode bidirectional display
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algorithm.
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+
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The other normative documents in the IDNA2008 document set establish
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criteria for valid labels, including listing the permitted
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+
characters. This document establishes additional validity criteria
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for labels in scripts normally written from right to left.
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+
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This specification is not intended to place any requirements on
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domain names that do not contain characters from such scripts.
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+
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+
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RFC 5893 IDNA Right to Left August 2010
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1.2. Background and History
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The "Stringprep" specification [RFC3454], part of IDNA2003, made the
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following statement in its Section 6 on the Bidi algorithm:
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3) If a string contains any RandALCat character, a RandALCat
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character MUST be the first character of the string, and a
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RandALCat character MUST be the last character of the string.
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(A RandALCat character is a character with unambiguously
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right-to-left directionality.)
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The reasoning behind this prohibition was to ensure that every
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component of a displayed domain name has an unambiguously preferred
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direction. However, this made certain words in languages written
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with right-to-left scripts invalid as IDN labels, and in at least one
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case (Dhivehi) meant that all the words of an entire language were
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forbidden as IDN labels.
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+
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This is illustrated below with examples taken from the Dhivehi and
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+
Yiddish languages, as written with the Thaana and Hebrew scripts,
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+
respectively.
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+
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RFC 3454 did not explicitly state the requirement to be fulfilled.
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Therefore, it is impossible to determine whether a simple relaxation
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of the rule would continue to fulfill the requirement.
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+
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While this document specifies rules quite different from RFC 3454,
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most reasonable labels that were allowed under RFC 3454 will also be
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allowed under this specification (the most important example of
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non-permitted labels being labels that mix Arabic and European digits
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+
(AN and EN) inside an RTL label, and labels that use AN in an LTR
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+
label -- see Section 1.4 for terminology), so the operational impact
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+
of using the new rule in the updated IDNA specification is limited.
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+
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+
1.3. Structure of the Rest of This Document
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+
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Section 2 defines a rule, the "Bidi rule", which can be used on a
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+
domain name label to check how safe it is to use in a domain name of
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+
possibly mixed directionality. The primary initial use of this rule
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+
is as part of the IDNA2008 protocol [RFC5891].
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Section 3 sets out the requirements for defining the Bidi rule.
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Section 4 gives detailed examples that serve as justification for the
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new rule.
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Section 5 to Section 8 describe various situations that can occur
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when dealing with domain names with characters of different
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directionality.
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+
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Only Section 1.4 and Section 2 are normative.
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+
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1.4. Terminology
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+
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The terminology used to describe IDNA concepts is defined in the
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Definitions document [RFC5890].
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+
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+
The terminology used for the Bidi properties of Unicode characters is
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+
taken from the Unicode Standard [Unicode52].
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+
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+
The Unicode Standard specifies a Bidi property for each character.
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+
That property controls the character's behavior in the Unicode
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+
bidirectional algorithm [Unicode-UAX9]. For reference, here are the
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+
values that the Unicode Bidi property can have:
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+
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o L - Left to right - most letters in LTR scripts
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+
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+
o R - Right to left - most letters in non-Arabic RTL scripts
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+
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+
o AL - Arabic letters - most letters in the Arabic script
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+
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+
o EN - European Number (0-9, and Extended Arabic-Indic numbers)
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+
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+
o ES - European Number Separator (+ and -)
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+
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o ET - European Number Terminator (currency symbols, the hash sign,
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+
the percent sign and so on)
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+
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+
o AN - Arabic Number; this encompasses the Arabic-Indic numbers, but
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+
not the Extended Arabic-Indic numbers
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+
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+
o CS - Common Number Separator (. , / : et al)
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+
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+
o NSM - Nonspacing Mark - most combining accents
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+
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+
o BN - Boundary Neutral - control characters (ZWNJ, ZWJ, and others)
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+
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+
o B - Paragraph Separator
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+
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+
o S - Segment Separator
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+
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+
o WS - Whitespace, including the SPACE character
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+
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+
o ON - Other Neutrals, including @, &, parentheses, MIDDLE DOT
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+
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+
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+
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Alvestrand & Karp Standards Track [Page 4]
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RFC 5893 IDNA Right to Left August 2010
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o LRE, LRO, RLE, RLO, PDF - these are "directional control
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characters" and are not used in IDNA labels.
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+
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+
In this memo, we use "network order" to describe the sequence of
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+
characters as transmitted on the wire or stored in a file; the terms
236
+
"first", "next", "previous", "beginning", "end", "before", and
237
+
"after" are used to refer to the relationship of characters and
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+
labels in network order.
239
+
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+
We use "display order" to talk about the sequence of characters as
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imaged on a display medium; the terms "left" and "right" are used to
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+
refer to the relationship of characters and labels in display order.
243
+
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+
Most of the time, the examples use the abbreviations for the Unicode
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+
Bidi classes to denote the directionality of the characters; the
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+
example string CS L consists of one character of class CS and one
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+
character of class L. In some examples, the convention that
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+
uppercase characters are of class R or AL, and lowercase characters
249
+
are of class L is used -- thus, the example string ABC.abc would
250
+
consist of three right-to-left characters and three left-to-right
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+
characters.
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+
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+
The directionality of such examples is determined by context -- for
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+
instance, in the sentence "ABC.abc is displayed as CBA.abc", the
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+
first example string is in network order, the second example string
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+
is in display order.
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+
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+
The term "paragraph" is used in the sense of the Unicode Bidi
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+
specification [Unicode-UAX9]. It means "a block of text that has an
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+
overall direction, either left to right or right to left",
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+
approximately; see the "Unicode Bidirectional Algorithm"
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+
[Unicode-UAX9] for details.
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+
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+
"RTL" and "LTR" are abbreviations for "right to left" and "left to
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+
right", respectively.
266
+
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+
An RTL label is a label that contains at least one character of type
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+
R, AL, or AN.
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+
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+
An LTR label is any label that is not an RTL label.
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+
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+
A "Bidi domain name" is a domain name that contains at least one RTL
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+
label. (Note: This definition includes domain names containing only
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+
dots and right-to-left characters. Providing a separate category of
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+
"RTL domain names" would not make this specification simpler, so it
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+
has not been done.)
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+
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+
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+
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+
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+
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RFC 5893 IDNA Right to Left August 2010
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+
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+
2. The Bidi Rule
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+
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+
The following rule, consisting of six conditions, applies to labels
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+
in Bidi domain names. The requirements that this rule satisfies are
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+
described in Section 3. All of the conditions must be satisfied for
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+
the rule to be satisfied.
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+
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+
1. The first character must be a character with Bidi property L, R,
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+
or AL. If it has the R or AL property, it is an RTL label; if it
296
+
has the L property, it is an LTR label.
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+
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+
2. In an RTL label, only characters with the Bidi properties R, AL,
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+
AN, EN, ES, CS, ET, ON, BN, or NSM are allowed.
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+
301
+
3. In an RTL label, the end of the label must be a character with
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+
Bidi property R, AL, EN, or AN, followed by zero or more
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+
characters with Bidi property NSM.
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+
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+
4. In an RTL label, if an EN is present, no AN may be present, and
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+
vice versa.
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+
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+
5. In an LTR label, only characters with the Bidi properties L, EN,
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+
ES, CS, ET, ON, BN, or NSM are allowed.
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+
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+
6. In an LTR label, the end of the label must be a character with
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+
Bidi property L or EN, followed by zero or more characters with
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+
Bidi property NSM.
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+
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+
The following guarantees can be made based on the above:
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+
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+
o In a domain name consisting of only labels that satisfy the rule,
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+
the requirements of Section 3 are satisfied. Note that even LTR
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+
labels and pure ASCII labels have to be tested.
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+
321
+
o In a domain name consisting of only LDH labels (as defined in the
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Definitions document [RFC5890]) and labels that satisfy the rule,
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+
the requirements of Section 3 are satisfied as long as a label
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+
that starts with an ASCII digit does not come after a
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+
right-to-left label.
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+
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+
No guarantee is given for other combinations.
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+
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+
3. The Requirement Set for the Bidi Rule
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+
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+
This document, unlike RFC 3454 [RFC3454], provides an explicit
332
+
justification for the Bidi rule, and states a set of requirements for
333
+
which it is possible to test whether or not the modified rule
334
+
fulfills the requirement.
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+
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+
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+
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Alvestrand & Karp Standards Track [Page 6]
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RFC 5893 IDNA Right to Left August 2010
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+
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+
All the text in this document assumes that text containing the labels
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+
under consideration will be displayed using the Unicode bidirectional
345
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algorithm [Unicode-UAX9].
346
+
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+
The requirements proposed are these:
348
+
349
+
o Label Uniqueness: No two labels, when presented in display order
350
+
in the same paragraph, should have the same sequence of characters
351
+
without also having the same sequence of characters in network
352
+
order, both when the paragraph has LTR direction and when the
353
+
paragraph has RTL direction. (This is the criterion that is
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+
explicit in RFC 3454). (Note that a label displayed in an RTL
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+
paragraph may display the same as a different label displayed in
356
+
an LTR paragraph and still satisfy this criterion.)
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+
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o Character Grouping: When displaying a string of labels, using the
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+
Unicode Bidi algorithm to reorder the characters for display, the
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+
characters of each label should remain grouped between the
361
+
characters delimiting the labels, both when the string is embedded
362
+
in a paragraph with LTR direction and when it is embedded in a
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+
paragraph with RTL direction.
364
+
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+
Several stronger statements were considered and rejected, because
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+
they seem to be impossible to fulfill within the constraints of the
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+
Unicode bidirectional algorithm. These include:
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+
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+
o The appearance of a label should be unaffected by its embedding
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+
context. This proved impossible even for ASCII labels; the label
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+
"123-A" will have a different display order in an RTL context than
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+
in an LTR context. (This particular example is, however,
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+
disallowed anyway.)
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+
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o The sequence of labels should be consistent with network order.
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+
This proved impossible -- a domain name consisting of the labels
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+
(in network order) L1.R2.R3.L4 will be displayed as L1.R3.R2.L4 in
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+
an LTR context. (In an RTL context, it will be displayed as
379
+
L4.R3.R2.L1).
380
+
381
+
o No two domain names should be displayed the same, even under
382
+
differing directionality. This was shown to be unsound, since the
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+
domain name (in network order) ABC.abc will have display order
384
+
CBA.abc in an LTR context and abc.CBA in an RTL context, while the
385
+
domain name (network) abc.ABC will have display order abc.CBA in
386
+
an LTR context and CBA.abc in an RTL context.
387
+
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+
389
+
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+
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+
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+
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+
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+
Alvestrand & Karp Standards Track [Page 7]
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RFC 5893 IDNA Right to Left August 2010
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+
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+
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+
One possible requirement was thought to be problematic, but turned
400
+
out to be satisfied by a string that obeys the proposed rules:
401
+
402
+
o The Character Grouping requirement should be satisfied when
403
+
directional controls (LRE, RLE, RLO, LRO, PDF) are used in the
404
+
same paragraph (outside of the labels). Because these controls
405
+
affect presentation order in non-obvious ways, by affecting the
406
+
"sor" and "eor" properties of the Unicode Bidi algorithm, the
407
+
conditions above require extra testing in order to figure out
408
+
whether or not they influence the display of the domain name.
409
+
Testing found that for the strings allowed under the rule
410
+
presented in this document, directional controls do not influence
411
+
the display of the domain name.
412
+
413
+
This is still not stated as a requirement, since it did not seem as
414
+
important as the stated requirements, but it is useful to know that
415
+
Bidi domain names where the labels satisfy the rule have this
416
+
property.
417
+
418
+
In the following descriptions, first-level bullets are used to
419
+
indicate rules or normative statements; second-level bullets are
420
+
commentary.
421
+
422
+
The Character Grouping requirement can be more formally stated as:
423
+
424
+
o Let "Delimiterchars" be a set of characters with the Unicode Bidi
425
+
properties CS, WS, ON. (These are commonly used to delimit labels
426
+
-- both the FULL STOP and the space are included. They are not
427
+
allowed in domain labels.)
428
+
429
+
* ET, though it commonly occurs next to domain names in practice,
430
+
is problematic: the context R CS L EN ET (for instance A.a1%)
431
+
makes the label L EN not satisfy the character grouping
432
+
requirement.
433
+
434
+
* ES commonly occurs in labels as HYPHEN-MINUS, but could also be
435
+
used as a delimiter (for instance, the plus sign). It is left
436
+
out here.
437
+
438
+
o Let "unproblematic label" be a label that either satisfies the
439
+
requirements or does not contain any character with the Bidi
440
+
properties R, AL, or AN and does not begin with a character with
441
+
the Bidi property EN. (Informally, "it does not start with a
442
+
number".)
443
+
444
+
445
+
446
+
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+
448
+
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+
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+
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RFC 5893 IDNA Right to Left August 2010
453
+
454
+
455
+
A label X satisfies the Character Grouping requirement when, for any
456
+
Delimiter Character D1 and D2, and for any label S1 and S2 that is an
457
+
unproblematic label or an empty string, the following holds true:
458
+
459
+
If the string formed by concatenating S1, D1, X, D2, and S2 is
460
+
reordered according to the Bidi algorithm, then all the characters of
461
+
X in the reordered string are between D1 and D2, and no other
462
+
characters are between D1 and D2, both if the overall paragraph
463
+
direction is LTR and if the overall paragraph direction is RTL.
464
+
465
+
Note that the definition is self-referential, since S1 and S2 are
466
+
constrained to be "legal" by this definition. This makes testing
467
+
changes to proposed rules a little complex, but does not create
468
+
problems for testing whether or not a given proposed rule satisfies
469
+
the criterion.
470
+
471
+
The "zero-length" case represents the case where a domain name is
472
+
next to something that isn't a domain name, separated by a delimiter
473
+
character.
474
+
475
+
Note about the position of BN: The Unicode bidirectional algorithm
476
+
specifies that a BN has an effect on the adjoining characters in
477
+
network order, not in display order, and are therefore treated as if
478
+
removed during Bidi processing ([Unicode-UAX9], Section 3.3.2, rule
479
+
X9 and Section 5.3). Therefore, the question of "what position does
480
+
a BN have after reordering" is not meaningful. It has been ignored
481
+
while developing the rules here.
482
+
483
+
The Label Uniqueness requirement can be formally stated as:
484
+
485
+
If two non-identical labels X and Y, embedded as for the test above,
486
+
displayed in paragraphs with the same directionality, are reordered
487
+
by the Bidi algorithm into the same sequence of code points, the
488
+
labels X and Y cannot both be legal.
489
+
490
+
4. Examples of Issues Found with RFC 3454
491
+
492
+
4.1. Dhivehi
493
+
494
+
Dhivehi, the official language of the Maldives, is written with the
495
+
Thaana script. This script displays some of the characteristics of
496
+
the Arabic script, including its directional properties, and the
497
+
indication of vowels by the diacritical marking of consonantal base
498
+
characters. This marking is obligatory, and both two consecutive
499
+
vowels and syllable-final consonants are indicated with unvoiced
500
+
combining marks. Every Dhivehi word therefore ends with a combining
501
+
mark.
502
+
503
+
504
+
505
+
506
+
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+
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+
RFC 5893 IDNA Right to Left August 2010
509
+
510
+
511
+
The word for "computer", which is romanized as "konpeetaru", is
512
+
written with the following sequence of Unicode code points:
513
+
514
+
U+0786 THAANA LETTER KAAFU (AL)
515
+
516
+
U+07AE THAANA OBOFILI (NSM)
517
+
518
+
U+0782 THAANA LETTER NOONU (AL)
519
+
520
+
U+07B0 THAANA SUKUN (NSM)
521
+
522
+
U+0795 THAANA LETTER PAVIYANI (AL)
523
+
524
+
U+07A9 THAANA LETTER EEBEEFILI (AL)
525
+
526
+
U+0793 THAANA LETTER TAVIYANI (AL)
527
+
528
+
U+07A6 THAANA ABAFILI (NSM)
529
+
530
+
U+0783 THAANA LETTER RAA (AL)
531
+
532
+
U+07AA THAANA UBUFILI (NSM)
533
+
534
+
The directionality class of U+07AA in the Unicode database
535
+
[Unicode52] is NSM (Nonspacing Mark), which is not R or AL; a
536
+
conformant implementation of the IDNA2003 algorithm will say that
537
+
"this is not in RandALCat" and refuse to encode the string.
538
+
539
+
4.2. Yiddish
540
+
541
+
Yiddish is one of several languages written with the Hebrew script
542
+
(others include Hebrew and Ladino). This is basically a consonantal
543
+
alphabet (also termed an "abjad"), but Yiddish is written using an
544
+
extended form that is fully vocalic. The vowels are indicated in
545
+
several ways, one of which is by repurposing letters that are
546
+
consonants in Hebrew. Other letters are used both as vowels and
547
+
consonants, with combining marks, called "points", used to
548
+
differentiate between them. Finally, some base characters can
549
+
indicate several different vowels, which are also disambiguated by
550
+
combining marks. Pointed characters can appear in word-final
551
+
position and may therefore also be needed at the end of labels. This
552
+
is not an invariable attribute of a Yiddish string and there is thus
553
+
greater latitude here than there is with Dhivehi.
554
+
555
+
The organization now known as the "YIVO Institute for Jewish
556
+
Research" developed orthographic rules for modern Standard Yiddish
557
+
during the 1930s on the basis of work conducted in several venues
558
+
since earlier in that century. These are given in, "The Standardized
559
+
560
+
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+
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Alvestrand & Karp Standards Track [Page 10]
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RFC 5893 IDNA Right to Left August 2010
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+
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+
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+
Yiddish Orthography: Rules of Yiddish Spelling" [SYO], and are taken
568
+
as normatively descriptive of modern Standard Yiddish in any context
569
+
where that notion is deemed relevant. They have been applied
570
+
exclusively in all formal Yiddish dictionaries published since their
571
+
establishment, and are similarly dominant in academic and
572
+
bibliographic regards.
573
+
574
+
It therefore appears appropriate for this repertoire also to be
575
+
supported fully by IDNA. This presents no difficulty with characters
576
+
in initial and medial positions, but pointed characters are regularly
577
+
used in final position as well. All of the characters in the SYO
578
+
repertoire appear in both marked and unmarked form with one
579
+
exception: the HEBREW LETTER PE (U+05E4). The SYO only permits this
580
+
with a HEBREW POINT DAGESH (U+05BC), providing the Yiddish equivalent
581
+
to the Latin letter "p", or a HEBREW POINT RAFE (U+05BF), equivalent
582
+
to the Latin letter "f". There is, however, a separate unpointed
583
+
allograph, the HEBREW LETTER FINAL PE (U+05E3), for the latter
584
+
character when it appears in final position. The constraint on the
585
+
use of the SYO repertoire resulting from the proscription of
586
+
combining marks at the end of RTL strings thus reduces to nothing
587
+
more, or less, than the equivalent of saying that a string of Latin
588
+
characters cannot end with the letter "p". It must also be noted
589
+
that the HEBREW LETTER PE with the HEBREW POINT DAGESH is
590
+
characteristic of almost all traditional Yiddish orthographies that
591
+
predate (or remain in use in parallel to) the SYO, being the first
592
+
pointed character to appear in any of them.
593
+
594
+
A more general instantiation of the basic problem can be seen in the
595
+
representation of the YIVO acronym. This acronym is written with the
596
+
Hebrew letters YOD YOD HIRIQ VAV VAV ALEF QAMATS, where HIRIQ and
597
+
QAMATS are combining points. The Unicode code points are:
598
+
599
+
U+05D9 HEBREW LETTER YOD (R)
600
+
601
+
U+05B4 HEBREW POINT HIRIQ (NSM)
602
+
603
+
U+05D5 HEBREW LETTER VAV (R)
604
+
605
+
U+05D0 HEBREW LETTER ALEF (R)
606
+
607
+
U+05B8 HEBREW POINT QAMATS (NSM)
608
+
609
+
The directionality class of U+05B8 HEBREW POINT QAMATS in the Unicode
610
+
database is NSM, which again causes the IDNA2003 algorithm to reject
611
+
the string.
612
+
613
+
614
+
615
+
616
+
617
+
618
+
Alvestrand & Karp Standards Track [Page 11]
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+
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+
RFC 5893 IDNA Right to Left August 2010
621
+
622
+
623
+
It may also be noted that all of the combined characters mentioned
624
+
above exist in precomposed form at separate positions in the Unicode
625
+
chart. However, by invoking Stringprep, the IDNA2003 algorithm also
626
+
rejects those code points, for reasons not discussed here.
627
+
628
+
4.3. Strings with Numbers
629
+
630
+
By requiring that the first or last character of a string be a member
631
+
of category R or AL, the Stringprep specification [RFC3454]
632
+
prohibited a string containing right-to-left characters from ending
633
+
with a number.
634
+
635
+
Consider the strings ALEF 5 (HEBREW LETTER ALEF + DIGIT FIVE) and 5
636
+
ALEF. Displayed in an LTR context, the first one will be displayed
637
+
from left to right as 5 ALEF (with the 5 being considered right to
638
+
left because of the leading ALEF), while 5 ALEF will be displayed in
639
+
exactly the same order (5 taking the direction from context).
640
+
Clearly, only one of those should be permitted as a registered label,
641
+
but barring them both seems unnecessary.
642
+
643
+
5. Troublesome Situations and Guidelines
644
+
645
+
There are situations in which labels that satisfy the rule above will
646
+
be displayed in a surprising fashion. The most important of these is
647
+
the case where a label ending in a character with Bidi property AL,
648
+
AN, or R occurs before a label beginning with a character of Bidi
649
+
property EN. In that case, the number will appear to move into the
650
+
label containing the right-to-left character, violating the Character
651
+
Grouping requirement.
652
+
653
+
If the label that occurs after the right-to-left label itself
654
+
satisfies the Bidi criterion, the requirements will be satisfied in
655
+
all cases (this is the reason why the criterion talks about strings
656
+
containing L in some cases). However, the IDNABIS WG concluded that
657
+
this could not be required for several reasons:
658
+
659
+
o There is a large current deployment of ASCII domain names starting
660
+
with digits. These cannot possibly be invalidated.
661
+
662
+
o Domain names are often constructed piecemeal, for instance, by
663
+
combining a string with the content of a search list. This may
664
+
occur after IDNA processing, and thus in part of the code that is
665
+
not IDNA-aware, making detection of the undesirable combination
666
+
impossible.
667
+
668
+
669
+
670
+
671
+
672
+
673
+
674
+
Alvestrand & Karp Standards Track [Page 12]
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+
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+
RFC 5893 IDNA Right to Left August 2010
677
+
678
+
679
+
o Even if a label is registered under a "safe" label, there may be a
680
+
DNAME [RFC2672] with an "unsafe" label that points to the "safe"
681
+
label, thus creating seemingly valid names that would not satisfy
682
+
the criterion.
683
+
684
+
o Wildcards create the odd situation where a label is "valid" (can
685
+
be looked up successfully) without the zone owner knowing that
686
+
this label exists. So an owner of a zone whose name starts with a
687
+
digit and contains a wildcard has no way of controlling whether or
688
+
not names with RTL labels in them are looked up in his zone.
689
+
690
+
Rather than trying to suggest rules that disallow all such
691
+
undesirable situations, this document merely warns about the
692
+
possibility, and leaves it to application developers to take whatever
693
+
measures they deem appropriate to avoid problematic situations.
694
+
695
+
6. Other Issues in Need of Resolution
696
+
697
+
This document concerns itself only with the rules that are needed
698
+
when dealing with domain names with characters that have differing
699
+
Bidi properties, and considers characters only in terms of their Bidi
700
+
properties. All other issues with scripts that are written from
701
+
right to left must be considered in other contexts.
702
+
703
+
One such issue is the need to keep numbers separate. Several scripts
704
+
are used with multiple sets of numbers -- most commonly they use
705
+
Latin numbers and a script-specific set of numbers, but in the case
706
+
of Arabic, there are two sets of "Arabic-Indic" digits involved.
707
+
708
+
The algorithm in this document disallows occurrences of AN-class
709
+
characters ("Arabic-Indic digits", U+0660 to U+0669) together with
710
+
EN-class characters (which includes "European" digits, U+0030 to
711
+
U+0039 and "extended Arabic-Indic digits", U+06F0 to U+06F9), but
712
+
does not help in preventing the mixing of, for instance, Bengali
713
+
digits (U+09E6 to U+09EF) and Gujarati digits (U+0AE6 to U+0AEF),
714
+
both of which have Bidi class L. A registry or script community that
715
+
wishes to create rules restricting the mixing of digits in a label
716
+
will be able to specify these restrictions at the registry level.
717
+
Some rules are also specified at the protocol level.
718
+
719
+
Another set of issues concerns the proper display of IDNs with a
720
+
mixture of LTR and RTL labels, or only RTL labels.
721
+
722
+
It is unrealistic to expect that applications will display domain
723
+
names using embedded formatting codes between their labels (for one
724
+
thing, no reliable algorithms for identifying domain names in running
725
+
text exist); thus, the display order will be determined by the Bidi
726
+
algorithm. Thus, a sequence (in network order) of R1.R2.ltr will be
727
+
728
+
729
+
730
+
Alvestrand & Karp Standards Track [Page 13]
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+
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+
RFC 5893 IDNA Right to Left August 2010
733
+
734
+
735
+
displayed in the order 2R.1R.ltr in an LTR context, which might
736
+
surprise someone expecting to see labels displayed in hierarchical
737
+
order. People used to working with text that mixes LTR and RTL
738
+
strings might not be so surprised by this. Again, this memo does not
739
+
attempt to suggest a solution to this problem.
740
+
741
+
7. Compatibility Considerations
742
+
743
+
7.1. Backwards Compatibility Considerations
744
+
745
+
As with any change to an existing standard, it is important to
746
+
consider what happens with existing implementations when the change
747
+
is introduced. Some troublesome cases include:
748
+
749
+
o An old program used to input the newly allowed label. If the old
750
+
program checks the input against RFC 3454, some labels will not be
751
+
allowed, and domain names containing those labels will remain
752
+
inaccessible.
753
+
754
+
o An old program is asked to display the newly allowed label, and
755
+
checks it against RFC 3454 before displaying. The program will
756
+
perform some kind of fallback, most likely displaying the label in
757
+
A-label form.
758
+
759
+
o An old program tries to display the newly allowed label. If the
760
+
old program has code for displaying the last character of a label
761
+
that is different from the code used to display the characters in
762
+
the middle of the label, the display may be inconsistent and cause
763
+
confusion.
764
+
765
+
One particular example of the last case is if a program chooses to
766
+
examine the last character (in network order) of a string in order to
767
+
determine its directionality, rather than its first. If it finds an
768
+
NSM character and tries to display the string as if it was a
769
+
left-to-right string, the resulting display may be interesting, but
770
+
not useful.
771
+
772
+
The editors believe that these cases will have a less harmful impact
773
+
in practice than continuing to deny the use of words from the
774
+
languages for which these strings are necessary as IDN labels.
775
+
776
+
This specification does not forbid using leading European digits in
777
+
ASCII-only labels, since this would conflict with a large installed
778
+
base of such labels, and would increase the scope of the
779
+
specification from RTL labels to all labels. The harm resulting from
780
+
this limitation of scope is described in Section 5. Registries and
781
+
private zone managers can check for this particular condition before
782
+
they allow registration of any RTL label. Generally, it is best to
783
+
784
+
785
+
786
+
Alvestrand & Karp Standards Track [Page 14]
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+
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+
RFC 5893 IDNA Right to Left August 2010
789
+
790
+
791
+
disallow registration of any right-to-left strings in a zone where
792
+
the label at the level above begins with a digit.
793
+
794
+
7.2. Forward Compatibility Considerations
795
+
796
+
This text is intentionally specified strictly in terms of the Unicode
797
+
Bidi properties. The determination that the condition is sufficient
798
+
to fulfill the criteria depends on the Unicode Bidi algorithm; it is
799
+
unlikely that drastic changes will be made to this algorithm.
800
+
801
+
However, the determination of validity for any string depends on the
802
+
Unicode Bidi property values, which are not declared immutable by the
803
+
Unicode Consortium. Furthermore, the behavior of the algorithm for
804
+
any given character is likely to be linguistically and culturally
805
+
sensitive, so while it should occur rarely, it is possible that later
806
+
versions of the Unicode Standard may change the Bidi properties
807
+
assigned to certain Unicode characters.
808
+
809
+
This memo does not propose a solution for this problem.
810
+
811
+
8. Security Considerations
812
+
813
+
The display behavior of mixed-direction text can be extremely
814
+
surprising to users who are not used to it; for instance, cut and
815
+
paste of a piece of text can cause the text to display differently at
816
+
the destination, if the destination is in another directionality
817
+
context, and adding a character in one place of a text can cause
818
+
characters some distance from the point of insertion to change their
819
+
display position. This is, however, not a phenomenon unique to the
820
+
display of domain names.
821
+
822
+
The new IDNA protocol, and particularly these new Bidi rules, will
823
+
allow some strings to be used in IDNA contexts that are not allowed
824
+
today. It is possible that differences in the interpretation of
825
+
labels between implementations of IDNA2003 and IDNA2008 could pose a
826
+
security risk, but it is difficult to envision any specific
827
+
instantiation of this.
828
+
829
+
Any rational attempt to compute, for instance, a hash over an
830
+
identifier processed by IDNA would use network order for its
831
+
computation, and thus be unaffected by the new rules proposed here.
832
+
833
+
While it is not believed to pose a problem, if display routines had
834
+
been written with specific knowledge of the RFC 3454 IDNA
835
+
prohibitions, it is possible that the potential problems noted under
836
+
"Backwards Compatibility Considerations" could cause new kinds of
837
+
confusion.
838
+
839
+
840
+
841
+
842
+
Alvestrand & Karp Standards Track [Page 15]
843
+
844
+
RFC 5893 IDNA Right to Left August 2010
845
+
846
+
847
+
9. Acknowledgements
848
+
849
+
While the listed editors held the pen, this document represents the
850
+
joint work and conclusions of an ad hoc design team. In addition to
851
+
the editors, this consisted of, in alphabetic order, Tina Dam, Patrik
852
+
Faltstrom, and John Klensin. Many further specific contributions and
853
+
helpful comments were received from the people listed below, and
854
+
others who have contributed to the development and use of the IDNA
855
+
protocols.
856
+
857
+
The particular formulation of the Bidi rule in Section 2 was
858
+
suggested by Matitiahu Allouche.
859
+
860
+
The team wishes, in particular, to thank Roozbeh Pournader for
861
+
calling its attention to the issue with the Thaana script, Paul
862
+
Hoffman for pointing out the need to be explicit about backwards
863
+
compatibility considerations, Ken Whistler for suggesting the basis
864
+
of the formalized "Character Grouping" requirement, Mark Davis for
865
+
commentary, Erik van der Poel for careful review, comments, and
866
+
verification of the rulesets, Marcos Sanz, Andrew Sullivan, and Pete
867
+
Resnick for reviews, and Vint Cerf for chairing the working group and
868
+
contributing massively to getting the documents finished.
869
+
870
+
10. References
871
+
872
+
10.1. Normative References
873
+
874
+
[RFC5890] Klensin, J., "Internationalized Domain Names for
875
+
Applications (IDNA): Definitions and Document
876
+
Framework", RFC 5890, August 2010.
877
+
878
+
[Unicode-UAX9] The Unicode Consortium, "Unicode Standard Annex #9:
879
+
Unicode Bidirectional Algorithm", September 2009,
880
+
<http://www.unicode.org/reports/tr9/>.
881
+
882
+
[Unicode52] The Unicode Consortium. The Unicode Standard, Version
883
+
5.2.0, defined by: "The Unicode Standard, Version
884
+
5.2.0", (Mountain View, CA: The Unicode Consortium,
885
+
2009. ISBN 978-1-936213-00-9).
886
+
<http://www.unicode.org/versions/Unicode5.2.0/>.
887
+
888
+
889
+
890
+
891
+
892
+
893
+
894
+
895
+
896
+
897
+
898
+
Alvestrand & Karp Standards Track [Page 16]
899
+
900
+
RFC 5893 IDNA Right to Left August 2010
901
+
902
+
903
+
10.2. Informative References
904
+
905
+
[RFC2672] Crawford, M., "Non-Terminal DNS Name Redirection",
906
+
RFC 2672, August 1999.
907
+
908
+
[RFC3454] Hoffman, P. and M. Blanchet, "Preparation of
909
+
Internationalized Strings ("stringprep")", RFC 3454,
910
+
December 2002.
911
+
912
+
[RFC5891] Klensin, J., "Internationalized Domain Names in
913
+
Applications (IDNA): Protocol", RFC 5891, August 2010.
914
+
915
+
[SYO] "The Standardized Yiddish Orthography: Rules of
916
+
Yiddish Spelling, 6th ed., New York, ISBN
917
+
0-914512-25-0", 1999.
918
+
919
+
Authors' Addresses
920
+
921
+
Harald Tveit Alvestrand (editor)
922
+
Google
923
+
Beddingen 10
924
+
Trondheim, 7014
925
+
Norway
926
+
927
+
EMail: harald@alvestrand.no
928
+
929
+
930
+
Cary Karp
931
+
Swedish Museum of Natural History
932
+
Frescativ. 40
933
+
Stockholm, 10405
934
+
Sweden
935
+
936
+
Phone: +46 8 5195 4055
937
+
Fax:
938
+
EMail: ck@nic.museum
939
+
940
+
941
+
942
+
943
+
944
+
945
+
946
+
947
+
948
+
949
+
950
+
951
+
952
+
953
+
954
+
Alvestrand & Karp Standards Track [Page 17]
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+