Priority 1 Item 1
Provide a text equivalent for every non-text element (e.g., via "alt", "longdesc", or in element content). This includes: images, graphical representations of text (including symbols), image map regions, animations (e.g., animated GIF's), applets and programmatic objects, ASCII art, frames, scripts, images used as list bullets, spacers, graphical buttons, all sounds, stand-alone audio files, audio tracks of video, and video.
Providing alternative text for non-text elements
<img src="corky.jpg" alt="Corky, the Emporia State University Logo." / >
<img src="corky.jpg" / >
Alternative Text Attribute
The alt tag (short for "alternate text attribute") is a textual description of a graphic or image. It is technically not a "tag" at all but an attribute of the image (IMG) tag in HTML code.
The alternative text attribute displays in most browsers as pop-up text when the user hovers his or her mouse pointer over an image. It also displays in place of a graphic when the 'view images' feature is turned of in a browser, or when the page is viewed with a text-only browsewr such as Lynx. Alternative text is also used by page-reading software to render graphical content accessible to blind or low-vision users.
More Resources
Using alt text for providing equivalent text content for images - WAI recommended technique.
Providing text equivalents for applets and programmatic objects - WAI recommended technique.
Text for images used as links - WAI recommended technique.
View WAI Checkpoint 1.1 - Provide a text equivalent for every non-text element (e.g., via "alt", "longdesc", or in element content).