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.
A text equivalent for every non-text element shall be provided (e.g., via
<alt>, <longdesc>, or in element content).
Here's the minimum required:
Equivalent alternatives for any multimedia presentation shall be synchronized
with the presentation.
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.)
- 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).
Web page design
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.
Web pages shall be designed so that all information conveyed with color
is also available without color, for example from context or markup.
Turn style sheets off in your browser and look at your pages. Are they useable?
Documents shall be organized so they are readable without requiring an associated
Server-side image maps
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.
Redundant text links shall be provided for each active region.
Client-side image maps
Use client-side image maps.
Each hotspot area needs an alt tag, too.
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.)
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!)
Row and column headers shall be identified for data tables.
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.
Frames shall be titled with text that facilitates frame identification and
Web page design
This is usually only a problem with advertisements that flicker. Don't make animations
Pages shall be designed to avoid causing the screen to flicker with a frequency
greater than 2 Hz and lower than 55 Hz.
Organization & equivalent alternatives
If you can't comply with the rules listed above, provide a text-only page, but make
sure you keep it up-to-date!
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.
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.
Applets, Objects, Plug-ins
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
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 ß1194.21(a) through (l).
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
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.
Skipping navigation links
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
A method shall be provided that permits users to skip repetitive navigation
Generally found on sites that have highly personal information inputs (credit
cards, 401(k)s, etc.). Probably not an issue on our sites.
When a timed response is required, the user shall be alerted and given sufficient
time to indicate more time is required.
Page author: Karen Smale
Last updated: Monday, 19-Jun-2006 11:24:57 EDT.
HEASARC Home |
Last modified: Monday, 19-Jun-2006 11:24:57 EDT