5.2 Abbreviations

This technique relates to the following sections of the guidelines:

Task:

Use the abbr and acronym elements to expand abbreviations.

Mark up abbreviations with abbr and use title to indicate the expansion. Abbreviations must be marked at every occurrence in the authored unit.

Acronyms and initialisms are types of abbreviations.  An acronym is an abbreviation made from the initial letters of a name or phrase that contains several words and may be pronounced as words. An initialism is the shortened form of a name or phrase made from the initial letters of words or syllables contained in that name or phrase. When using HTML 4.01, XHTML 1.0 or XHTML 1.1,  initialisms and acronyms may be marked up using the acronym tag.  XHTML 2.0 proposes eliminating the acronym element in favor of the more general abbr element.

User Agent Notes:

Visual User Agents
Most graphical user agents, render text enclosed within an abbr or acronym element with a dotted line below it. Also, when the mouse hovers over the element, the expansion is displayed as a tool tip.
Internet Explorer 6 and below

Internet Explorer 6.0 and prior versions do not support the abbr element.  Items marked using the abbr element are not displayed with any additional formatting nor does the expanded version display as a tooltip when the mouse hovers over the item.  Future versions are expected to fully support the abbr element. 

JAWS 6.2
WindowEyes 5.0
Home Page Reader 3.04

These assistive technologies support the abbr and acronym elements. They all can be set to speak the title attribute when these elements are encountered.  Within a given product the abbr and acronym elements are rendered the same.

Example:

These examples show how to use the abbr element properly.

<p>Sugar is commonly sold in 5 <abbr title="pound">lb.<abbr> bags.</p>
<p>Welcome to the <abbr title="World Wide Web">WWW</abbr>!</p>

This example shows how to use the acronym element.

<p>The use of <acronym title="Keep It Simple Stupid">KISS</acronym> became popular in ...</p>

Resources: