https://bugs.documentfoundation.org/show_bug.cgi?id=66580
--- Comment #24 from [email protected] --- The latest ISO standard for PDF (ISO 32000-2:2020) no longer prohibits custom keys in trailers - in fact, it explicitly permits keys that are 2nd-class names: "The PDF file trailer dictionary may also contain any second-class name as described in Annex E, "Extending PDF"." Historically the issue was that a lot of SW did not maintain all custom trailer entries when applying incremental updates so software that relied on their presence got broken if such files were later edited. Also, conventional trailer dictionaries don't exist when using (non-hybrid) cross-reference streams and software that converts to conventional PDFs to cross-reference stream-based PDFs also need to remember to copy custom keys across when converting. Basically its high risk putting stuff there... Depending on what the data is (just DocChecksum??), there are more appropriate and reliable places to save the data in the PDF DOM: Document Catalog PieceInfo, XMP Metadata, use a proper DigSig if the checksum is somehow important for detecting tampering, ... -- You are receiving this mail because: You are the assignee for the bug.
