HTML and CSS Reference
Figure 10-4. A color picker example suggested by W3C 
Information and structure must be separated from presentation to enable different presentations. Various color
combinations can be provided for the text and background of the main content along with component groups within
the web page.
Abbreviations, Definitions, and Foreign Words
The full form of words may precede their shortenings. Abbreviations might have an inline expansion or explanation
they are associated with the first time they occur within a web page. Definitions may be provided by the abbr and
acronym elements for all abbreviations. Defined words can be enclosed by the dfn element. Terms, abbreviations,
initialism, and acronyms can be linked to their definitions in order to provide the highest level of accessibility. Terms
and phrases written as definition list items are the most accessible. They may be collected on a glossary page available
through a simple hyperlink provided by the link element. Alternatively, a search function can be embedded that
provides the definitions through an external online dictionary. Beyond abbreviations, all words or phrases used in an
unusual way or restricted manner can be made more accessible with a definition.
The pronunciation of a special or foreign word provided immediately after the word at least the first time it
occurs within a web page contributes to AAA conformance. Other instances can alternatively provide a link to a list of
The default language of web documents must be identified in the HTTP header as well as by the lang and/or
xml:lang attribute on the html element in the markup. This is also vital for web pages with Flash content because
embedded Flash objects inherit the language settings provided by the lang and/or xml:lang attributes. Document
sections written in a language other than the default language must be clearly identified on their containers.
To ensure text direction for bidirectional inline content, the right-to-left Unicode marks ( ‏ , ‏ , or
U+200F ) and left-to-right Unicode marks ( ‎ , ‎ or U+200E ) must be applied.
Text direction of inline content must apply the dir attribute to clearly indicate text direction.