Techniques for WCAG 2.0

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H54: Using the dfn element to identify the defining instance of a word


HTML 4.x and XHTML 1.x

This technique relates to:

User Agent and Assistive Technology Support Notes


The objective of this technique is to use the dfn to mark the use of a word or phrase where it is defined. The dfn element is used to indicate the defining instance of the enclosed term. In other words, it marks the occurrence of the term where the term is defined. Note that it encloses the term, not the definition. This technique would be used in combination with G112: Using inline definitions to provide the definition.


Example 1

The following code snippet demonstrates the use of the dfn element.

<p>The Web Content Accessibility Guidelines require that non-text content
has a text alternative. <dfn>Non-text content</dfn> is content that is not a sequence
of characters that can be programmatically determined or where the sequence is
not expressing something in human language; this includes ASCII Art (which is a
pattern of characters), emoticons, leetspeak (which is character substitution), and
images representing text .</p>


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  1. Identify all words that are defined inline in the text, that is, where the definition occurs in a sentence near an occurrence of the word.

  2. Check that each word that is defined inline is contained in a dfn element.

Expected Results