It seems that this information is there by mistake:
Definition
Alternative text is provided for visual content (e.g., via the [HTML] alt attribute).
Examples
Thanks, yes, I likely used the alt text page as a template for splitting out all the values and forgot to update that definition. I'll get it fixed asap.
It seems that this information is there by mistake: Definition Alternative text is provided for visual content (e.g., via the [HTML] alt attribute). Examples
This is found on: https://kb.daisy.org/publishing/docs/metadata/schema.org/accessibilityFeature/pageBreakMarkers.html