Sami MäättäAccessibility metadata and access modes
Should you add accessibility metadata to your website or digital publication?
Well, yeah. It helps to "to enable discovery no matter how the publication is distributed or consumed."
Introducing schema.org's accessibility metadata step-by-step.
(Here I talk about websites and digital books as "publications".)
Access modes describe in which ways your publication's content can be accessed (for code examples go to Daisy's definition of accessMode).
Textual
If you define your publication to be "textual" it means that the content is at least partly in text.
You wouldn't use "textual" property at all if you had a portfolio or art showcase page without text.
Visual
Use this if the publication has "images, graphics or video" and it is relevant to understand the content of the page. If you only have decorative images then don't use this property.
So, use when you talk reference the image or it's a flow chart that adds to the content on the page.
Auditory
Similar with images: If the audio adds to the information on the page, then you should use this property.
If you have one of those websites that have "soothing nature sounds" in the background, this is not for you. Except if the site is about wild life in Canada and you play a recording of that!
Tactile
Do you have an accompanying piece of tactile material with your publication? Probably not.
Although, you can use "tactile" property if you happen to have braille-formatted text in the publication (for example a visual representation of the braille letters in Unicode). Using a braille display doesn't count as your publication being "tactile".
Have you used these? Are you going to now?
Share with those who would benefit!