···131131 - `v` (hash link, **nullable**): reference to the record data for this key.
132132 - when **null**: the record is included in the archive and will follow (implicit CID)
133133 - when **non-null**: the record exists but is not included in the archive
134134- - `t` (hash link, nullable): link to a subtree that sorts to the right of this entry's key and to the left of the next entry's key. same rules as `l`:
135135- - when **absent**: there is no left subtree
136136- - when **null**: the left subtree is present and will follow in the archive (implicit CID)
137137- - when **non-null**: the left subtree exists but is abset from the archive
134134+ - `t` (hash link, **optional and nullable**): link to a subtree that sorts to the right of this entry's key and to the left of the next entry's key. same rules as `l`:
135135+ - when **absent**: there is no subtree here subtree
136136+ - when **null**: the subtree is present and will follow in the archive (implicit CID)
137137+ - when **non-null**: the subtree exists but is abset from the archive
138138139139140140### record