User Agent Accessibility Standards

The User Agent Accessibility Guidelines Working Group (U​AWG)​, also part of the World Wide Web Consortium (W​3C) ​Web Accessibility Initiative (W​AI)​, has published accessibility guidelines for user agents (such as Web browsers, media players, and assistive technologies0, namely UAAG (User Agent Accessibility Guidelines):

http://www.w3.org/TR/UAAG10/