DA in signature field dictionary: really required?

[a20dev]

According to FieldSig.tsv (all versions), the DA entry is required for signature fields. However, I cannot find wording to that effect in ISO 32000-2:2020.

12.7.5.5 (Signature Fields) says "The field dictionary representing a signature field may contain the additional entries listed in Table 235 [...] as well as the standard entries described in Table 226 [...l]". DA is not in those tables. (Existing practice is that DA is optional for signature fields.)

DA is required only for fields containing variable text. ISO 32000-2:2020 does not specify that signature fields are fields containing variable text.

Note that a signature field (or rather the appearance of its widget annotation) does not have to contain text once it is signed, it may also contain just an image.

[petervwyatt]

See also Issue #28.

[a20dev]

About #28: the only annotations that have a DA entry are freetext annotations. In a signature field dictionary merged with its widget annotation dictionary, the DA entry belongs to the field dictionary.

[petervwyatt]

Resolved in ./tsv/latest but data model not propagated to the PDF version specific file sets.
Thanks for reporting!

The "required if field contains variable text" is not yet encoded into the data model - that is part of Issue #28. But I added as a comment (right-most "Note" field) to the DA key in FieldSig.tsv.