ReadonlycontentAnnotation contents from /Contents, or null; Table 166.
ReadonlycreationRaw /CreationDate PDF date string, if any. See ISO 32000-2:2020,
7.9.4 and Table 172.
ReadonlymodificationRaw /M PDF date string (e.g. D:20240131120000+09'00'), if any.
See ISO 32000-2:2020, 7.9.4 and Table 166.
ReadonlysubjectMarkup annotation subject from /Subj, or null; Table 172.
ReadonlytitleMarkup annotation title from /T, or null; Table 172.
Markup metadata shared with link annotations. The represented PDF entries are specified by ISO 32000-2:2020, 12.5.2, Table 166 and 12.5.6.2, Table 172.