CofC Web Accessibility Guidelines- Rule (D)

(d) Documents shall be organized so they are readable without requiring an associated style sheet.

Translation: Since style sheets can be used to hide or position content, they can affect the readability of the page. If you use a style sheet, it should contain only formatting information. All content should be in the page, and the page should be readable without the style sheet.

Some background: A style sheet is a file that contains formatting information for the page. They can contain information on colors, fonts, and positioning. When used properly, style sheets are very useful. They make it easy for a site to have a consistent look and feel without having to define fonts and colors over and over again.

The goal is to have all the content (text and pictures) in the web page and all the formatting information in the style sheet.

If you've never used (or heard of) style sheets, then you probably don't have to worry about this. A style sheet is something you create, not something that happens by itself. If you didn't make it, it's not there.

What to do: The only way to really know if your page complies is to submit it to one of the testing sites without the style sheet attached. If it not possible to comply, a text-only page should be supplied via link. See rule (k) for some notes about maintaining duplicate text pages.