veraPDF validation failed, whereas PAC finds all fine

[eta-orionis]

Trying to validate the attached file out.pdf, which was generated with openhtmltopdf. VeraPDF 1.26.4/Windows on OpenJDK finds an error (see attached reports), whereas the latest PAC says all is fine.

Is this a bug in veraPDF, is PAC wrong in their implementation of the PDF/UA Checks, or is veraPDF simply incompatible with the PDFs created by openhtmltopdf?

out.pdf
veraPDF-reports.zip

[bdoubrov]

@eta-orionis thanks for reporting the issue. Your attached document fails the checkpoint 28-012 of the Matterhorn 1.1 protocol:

A link annotation does not include an alternate description in its Contents entry

I see the alternative description for links is specified on the level of the parent Link structure element. Maybe this is the reason why PAC does not report missing Contents entry as an issue. We'll double check this with the PDF/UA technical working group of PDF Association.

[eta-orionis]

Thank you @bdoubrov !

I asked the PAC team as well, and indeed, that is the reason on their side. Thanks for offering to check with the PDF/UA WG; it would be useful to have an authoritative answer on the topic, as the new legal climate regarding accessibility in the EU is already full of uncertainties and nobody is served by having the two leading PDF validators disagree.