Web Accessibility Policy of the State of Maine
5. Image Maps
5.1 - Provide alternate text for each area in client-side image maps.
Image maps are images divided into multiple "areas," with each area having its own hypertext link.
Just as images must have alternate text, each area of an image map must also have appropriate alternate text for use when the image is not displayed.
Use alternate text that indicates the function or destination of the link for each area of a client-side image map. The image itself should have alternate text that indicates the overall function of the image map.
Ref: WCAG 1.1; 508 a
5.2 - Avoid using server-side image maps.
While client-side image maps and server-side image maps look and operate similarly, they are technically very different. Because of the way server-side image maps work, all information about the image and links is stored at the web server and is not available to the user's web browser or assistive technology.
Screen readers cannot identify or read the separate areas or links within server-side image maps.
Whenever possible, use client-side image maps instead of server-side image maps. If server-side image maps must be used, provide a set of text links that duplicate all the functions/destinations included in the image map.
Ref: WCAG 1.2, 9.1; 508 e, f