Am Thu, 10 Jul 2025 10:54:06 +0200 schrieb Hans Hagen via ntg-context:
so then i thought, well, let's update verapdf and for sure a document that validated a while ago doesn't now .. one can wondert how many validated documents there are around that actually invalidate now ...
context uses a lot of Document -> NonStruct -> content items constructions. That is invalid in PDF 2.0. Document can not contain content items, and NonStruct counts as "transparent" for such rules. But until recently verapdf didn't correctly handle the transparency of NonStruct (and Part and Div) and didn't complain but this has been corrected in an update. https://github.com/veraPDF/veraPDF-library/issues/1520
- The file validates successfully, but there are lots of "Nested MCID" warnings.
But not invalid, right?
Nesting marked content sequences with MCID is invalid: ISO 32000-2 14.7.5.1.1 Content items Content items shall be leaf nodes of the structure tree; that is, they shall not have other content items nested within them for purposes of logical structure. ... A marked-content sequence corresponding to a structure content item shall not have another marked-content sequence for a structure content item nested within it though non-structural marked-content shall be allowed. context should also add /MarkInfo << /Marked true >> to the catalog if the document is tagged. I do not claim that it is really clear from the spec that it is required but the PDF/UA TWG confirmed that it should be there, and at some time the spec will perhaps clarify that or some validator or consumer will test for it. -- Ulrike Fischer http://www.troubleshooting-tex.de/