core + bib (Bibliographic Extension): terms relating to books and bibliography.

accessibilitySummary

Canonical URL: http://schema.org/accessibilitySummary

Thing > Property > accessibilitySummary

A human-readable summary of specific accessibility features or deficiencies, consistent with the other accessibility metadata but expressing subtleties such as "short descriptions are present but long descriptions will be needed for non-visual users" or "short descriptions are present and no long descriptions are needed."
Values expected to be one of these types
Text
Used on these types
CreativeWork

Source

https://github.com/schemaorg/schemaorg/issues/1100

Schema Version 3.3