The Specification

Update November 09, 2021

This Project is no longer maintained here.  This project’s work has been moved to the W3C and has been taken up in a Community Group.  For more information please visit the new Accessibility Discoverability Vocabulary For Community Group.

To review or report issues with the Accessibility Properties for Discoverability Vocabulary, please refer to the vocabulary’s GitHub issue tracker.

Original Specification (Outdated)

The specification is maintained at the W3C’s WebSchemas/Accessibility page.

A majority of properties and terms in the Accessibility Metadata specification are a subset derived from the IMS Global Learning Consortium’s Access for All specificationIMS Global Learning Consortium has licensed these properties to under the Creative Commons Attribute-ShareAlike License (version 3.0) so that they can be used under‘s corresponding terms and conditions. Any other organizations or initiatives that would like to adopt IMS Global’s AccessForAll for other purposes are requested to coordinate directly with IMS Global.

For applications of this specification and its relationships with previous metadata efforts, you can also find

  • A robust set of examples, which helped prove out the tags as we developed the specification. These should be helpful to content creators and distributors as you try to understand how these tags would be used in your content and catalogs.
  • Live examples, where we show the before and after and the type of tagging needed to enable the content for microdata-based search. There are even canned links for microdata-enabled search.
  • A crosswalk that relates our specification to work of LRMI, Access for All, Dublin Core Accessibility and Onix.
  • Definitions for most of the expected values can be found in the IMS Global Access for All (AfA) Information Model Data Element Specification.

For comments or discussion, enter the discussion on our Discuss page.