HTML 5 accessibility principles

The W3C HTML Working Group developed a series of principles for HTML5 in the areas of compatibility, utility and interoperability.

Compatibility

To support existing content and allow concepts to degrade gracefully.

Utility

To make sure that HTML can be used effectively for its many intended purposes.

Interoperability

To improve the chances of HTML implementations being truly interoperable.

Universal Access

To make sure that all HTML features are designed for universal access.

Further information can be found at:
http://www.w3.org/TR/html-design-principles/