Section 508 Rules

These are the section 508 rules that all government web sites must comply with. Some of the "official" rules are rather opaque. I've provided examples and translations to plain (I hope) English in italics after every item.

  1. Text equivalent
    A text equivalent for every non-text element shall be provided (e.g., via <alt>, <longdesc>, or in element content).

  2. See Examples

  3. Equivalent alternatives
    Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation.

  4. Here's the minimum required:
    • For every video you must describe what a blind person is missing and write it out in ascii text (their automated screen readers will read it aloud to them).
    • For all audio files and video voiceovers you must transcribe what is spoken and write it out in ascii text (so the deaf can read it).
    These should be linked on the page near the link to the multimedia file. If it's a video with voiceover, you can combine these into one linked file. (See this StarChild example.)

  5. Web page design
    Web pages shall be designed so that all information conveyed with color is also available without color, for example from context or markup.

  6. This applies to color-coded bullets that have different meanings, color used in table cells to convey meaning, colored text where one color has one meaning and another color has another, etc.

  7. Organization
    Documents shall be organized so they are readable without requiring an associated style sheet.

  8. Turn style sheets off in your browser and look at your pages. Are they useable?

  9. Server-side image maps
    Redundant text links shall be provided for each active region.

  10. Unless your pages are old, you probably don't have server-side image maps. Redundant text links are a good idea for ANY image map.

  11. Client-side image maps
    Client-side image maps shall be provided instead of server-side images maps except where the regions cannot be defined with an available geometric shape. (Arbitrary polygon shapes avail.)

  12. Use client-side image maps. Each hotspot area needs an alt tag, too.

  13. Data tables
    Row and column headers shall be identified for data tables.

  14. Table headers need the TH tag (instead of TD) - this tells screen readers to give them emphasis and to read them in association with the proper cells. (You'll also automatically have boldface in your headers!)

  15. Multi-logic row or column headers
    Markup shall be used to associate data cells and header cells for data tables that have two or more logical levels of row or column headers.

  16. Rare.

  17. Frames
    Frames shall be titled with text that facilitates frame identification and navigation.

  18. See example.

  19. Web page design
    Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2 Hz and lower than 55 Hz.

  20. This is usually only a problem with advertisements that flicker. Don't make animations that flicker!

  21. Organization & equivalent alternatives
    A text-only page, with equivalent information or functionality, shall be provided to make a web site comply with the provisions of this part, when compliance cannot be accomplished in any other way. The content of the text-only page shall be updated whenever the primary page changes.

  22. If you can't comply with the rules listed above, provide a text-only page, but make sure you keep it up-to-date!

  23. Scripting languages
    When pages utilize scripting languages to display content, or to create interface elements, the information provided by the script shall be identified with functional text that can be read by assistive technology.

  24. Turn off JavaScript and make sure your site works without it.

  25. Applets, Objects, Plug-ins
    When a web page requires that an applet, plug-in or other application be present on the client system to interpret page content, the page must provide a link to a plug-in or applet that complies with 1194.21(a) through (l).

  26. If you have PDF files, Word documents or PS files, or if you use Shockwave or Flash on your site, provide a link to the plugins or s/w if available. The address for Acrobat Reader is:

  27. Forms
    When electronic forms are designed to be completed on-line, the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues.

  28. This one is a stickler! See some examples of the label element, which allows those with poor motor control to have a larger area to hit when clicking a radio button, for example. Text areas should have clear lables or contain placeholding text.

  29. Skipping navigation links
    A method shall be provided that permits users to skip repetitive navigation links.

  30. If you have menu bars at the top of all your pages (or in a table cell to the top or left of your content), please add a "skip navigation" link that takes the user to the content of the page (put an anchor before the content). For an example, scroll to the top of this page and run your mouse around just above the NASA logo to find the link. Click it. This helps people who use screen readers. The readers will read all the links first (your navigation included) every time it reads a page. Once someone has heard the 20 links at the top of your page once or twice, they probably don't want to hear them all again... Give them a way to skip over them (the first link they hear should be "skip navigation").

  31. Timed Response
    When a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required.

  32. Generally found on sites that have highly personal information inputs (credit cards, 401(k)s, etc.). Probably not an issue on our sites.


Page author: Karen Smale
Last updated: Monday, 19-Jun-2006 11:24:57 EDT.

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Last modified: Monday, 19-Jun-2006 11:24:57 EDT