Priority 1 Item 5
Client-side image maps should be provided instead of server-side image maps. If you must use server-side image maps, provide redundant text links for each link on the image map.
Using a client-side image map
<img src="images/p5-ImageMap.gif" alt="Sample Client-side Image Map." usemap="#p5_ImageMap_Map" /> <map name="p5_ImageMap_Map" id="p5_ImageMap_Map"> <area shape="rect" alt="Image Map - Link Three Example." coords="286,21,387,45" href="#" /> <area shape="rect" alt="Image Map - Link Two Example." coords="182,21,270,44" href="#" /> <area shape="rect" alt="Image Map - Link One Example." coords="79,23,162,42" href="#" /> </map>
How do "image maps" work?
An "image map" is a picture on a web page that provides different "links" to other web pages, depending on where a user clicks on the image. There are two basic types of image maps: "client-side image maps" and "server-side image maps." Unlike server-side image maps, the client-side image map allow an author to assign text to each image map “hot spots.” This feature means that someone using a screen reader can easily identify and activate regions of the map. (The Access Board)
More Resources
Providing alternative links when using the OBJECT element - WAI recommended technique.
Alt text and client side image maps - CAST recommended technique.
View WAI Checkpoint 1.2 - Provide redundant text links for each active region of a server-side image map.
View WAI checkpoint 9.1 - Provide client-side image maps instead of server-side image maps except where the regions cannot be defined with an available geometric shape.
Use client-side image maps and be sure to provide alternative text for each AREA of the map. If you must use server-side image maps, then provide equivalent redundant text links for all active regions of the map.
IBM Web Checkpoint 2 http://www-306.ibm.com/able/guidelines/web/webmaps.html