Accessibility standards
From Joomla! Documentation
There are two primary standards that are used as benchmarks for Web Accessibility.
Web Content Accessibility Guidelines (WCAG)[edit]
The Web Content Accessibility Guidelines are produced and maintained by the World Wide Web consortium (W3C). WCAG's standards are based on four Principles: Perceivable, Operable, Understandable and Robust. Get more information about the Web Content Accessibility Guidelines 2.0 See also the Introduction to Web Accessibility.
Section 508[edit]
Section 508 is a US federal law enacted in 1998. Its basis was for use in all government agencies but it has since been adopted by the wider community as a benchmark for web accessibility. For more information on Section 508, see the the official website.