Alt text—the text that pops up when you mouse over an image—is one of those topics that people always seem to have questions about. Why do we need alt text? How do you write it? And how do you write alt text for those tricky images, like maps, graphs, charts, or diagrams?

To help with this, we've recently reorganized and updated our alt text standards to include information about the many different types of alt text and the guidelines for writing them. There are lots of examples of alt text currently used on the Web site, and a link to the 2007 Webinar about Section 508. There's also a section on writing captions, and how you should combine these with your alt text to provide the most information to all of your readers.

As always, if you have any questions or thoughts about this update, please leave a comment!