I have created samples of accessibility metadata by material type, corresponding with MARC 21 (Field 341) and schema.org (EPUB Accessibility / ISO/IEC 23761).
I express samples of schema.org (EPUB Accessibility / ISO/IEC 23761) by inputting
1 in the corresponding value for each vocabulary.
To be honest, I’m not so sure about the MARC21 samples because MARC21’s rules are so complicated.
In MARC21, we need to input the information equivalent to schema.org’s `accessibilityFeature by using the following 341’ｓ subfields $b,$c,$d and $e.
$b – Textual assistive features (R) Text-based assistive features
$c – Visual assistive features (R) Visual-based assistive features
$d – Auditory assistive features (R) Speech-based assistive features.
$e – Tactile assistive features (R) Tactile-based assistive features
We may need to determine which of $b to $e we apply for each
accessibilityFeatures values each time cataloging. There can be easily divisions of judgment for each value, each material among catalogers.
I also tried to create a mapping table of between 341 $b to $e and the
accessibilityFeature‘s values. However, this is just a suggestion based on my understanding.