Correctness of language attribute 

This quality check is included in PAC 2024.0. It has been removed in PAC 2024.1 and later versions.
The correctness of the language attribute is still checked within PDF/UA > Basic > Natural Language.

The specified language of a PDF document must correspond to the language codes as defined in RFC 3066. This check does not check full compliance with the standard, but rather formal correctness. For example, the check allows "de-DE", but not "de".

To fix this quality check, make sure that the specified language for the document is a valid language code.

Detailed explanation

Document language is missing a sub-tag, omits the hyphen, or is otherwise malformedFAIL
Document language is specification-compliant PASS