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Comparison of Section 508 and WCAG Priority 1 Checkpoints

by P.J. Gardner

This report provides a side-by-side comparison of:

The accessibility standards for web content (Subpart B, §1194.22, "Web-based intranet and internet information and applications") identified under Section 508 of the Rehabilitation Act (Section 508) by the U.S. Architectural and Transportation Barriers Compliance Board (Access Board).
The Priority 1 checkpoints of the Web Content Accessibility Guidelines 1.0 (WCAG 1.0), published by the World Wide Web Consortium's (W3C) Web Accessibility Initiative (WAI).

Note: More up-to-date versions of both standards are available. For more information, visit:

Section 508 Refresh (April 2008)
New Recommendations for Section 508 (summary)
Web Content Accessibility Guidelines 2.0 (December 2008)

This document is divided into sections, as follows:

Guidelines that Correspond
Text of Guidelines that Correspond
Section 508 Differences
Text of Section 508 Differences
WCAG 1.0 Priority 1 Differences
Text of WCAG 1.0 Priority 1 Differences

Guidelines that Correspond

The Access Board issued the final accessibility standards for electronic and information technology covered by Section 508. During their analysis, they interpreted paragraphs (a) through (k) of Section 508 as consistent with the Priority 1 Checkpoints of WCAG 1.0.

The following chart outlines the equivalent sections from each standard. The links in the table identify sections of this document that contain the exact wording of each standard.

Section 508 and WCAG Guidelines That Correspond
Topic:	Section 508:	WCAG 1.0:
Text Equivalents:	(a)	1.1
Multimedia Alternatives:	(b)	1.4
Color:	(c)	2.1
Style Sheets:	(d)	6.1
Server-Side Image Maps:	(e)	1.2
Client-Side Image Maps:	(f)	9.1
Table Headers:	(g)	5.1
Complex Tables:	(h)	5.2
Frames:	(i)	12.1
Screen Flicker:	(j)	7.1
Alternative Pages:	(k)	11.4

Text of Guidelines that Correspond

Text Equivalents

Section 508, §1194.22(a): A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content).

WCAG 1.0, Checkpoint 1.1: 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 GIFs), applets and programmatic objects, ascii art, frames, scripts, images used as list bullets, spacers, graphical buttons, sounds (played with or without user interaction), stand-alone audio files, audio tracks of video, and video.

Multimedia Alternatives

Section 508, §1194.22(b): Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation.

WCAG 1.0, Checkpoint 1.4: For any time-based multimedia presentation (e.g., a movie or animation), synchronize equivalent alternatives (e.g., captions or auditory descriptions of the visual track) with the presentation.

Color

Section 508, §1194.22(c): Web pages shall be designed so that all information conveyed with color is also available without color, for example from context or markup.

WCAG 1.0, Checkpoint 2.1: Ensure that all information conveyed with color is also available without color, for example from context or markup.

Style Sheets

Section 508, §1194.22(d): Documents shall be organized so they are readable without requiring an associated style sheet.

WCAG 1.0, Checkpoint 6.1: Organize documents so they may be read without style sheets. For example, when an HTML document is rendered without associated style sheets, it must still be possible to read the document.

Server-Side Image Maps

Section 508, §1194.22(e): Redundant text links shall be provided for each active region of a server-side image map.

WCAG 1.0, Checkpoint 1.2: Provide redundant text links for each active region of a server-side image map.

Client-Side Image Maps

Section 508, §1194.22(f): Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape.

WCAG 1.0, Checkpoint 9.1: Provide client-side image maps instead of server-side image maps except where the regions cannot be defined with an available geometric shape.

Table Headers

Section 508, §1194.22(g): Row and column headers shall be identified for data tables.

WCAG 1.0, Checkpoint 5.1: For data tables, identify row and column headers.

Complex Tables

Section 508, §1194.22(h): 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.

WCAG 1.0, Checkpoint 5.2: For data tables that have two or more logical levels of row or column headers, use markup to associate data cells and header cells.

Frames

Section 508, §1194.22(i): Frames shall be titled with text that facilitates frame identification and navigation.

WCAG 1.0, Checkpoint 12.1: Title each frame to facilitate frame identification and navigation.

Screen Flicker

Section 508, §1194.22(j): Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2 Hz and lower than 55 Hz.

WCAG 1.0, Checkpoint 7.1: Until user agents allow users to control flickering, avoid causing the screen to flicker.

Alternative Pages

Section 508, §1194.22(k): 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.

WCAG 1.0, Checkpoint 11.4: If, after best efforts, you cannot create an accessible page, provide a link to an alternative page that uses W3C technologies, is accessible, has equivalent information (or functionality), and is updated as often as the inaccessible (original) page.

Section 508 Differences

The Access Board declared that five paragraphs of Section 508 differ from the Priority 1 checkpoints of Web Content Accessibility Guidelines (WCAG 1.0)

Section 508 Differences
Topic:	Section 508:
Script Alternatives:	(l)
Applet Links:	(m)
Forms:	(n)
Skip Navigation Links:	(o)
Timed Responses:	(p)

Text of Section 508 Differences

Script Alternatives

Section 508, §1194.22(l): 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.

Applet Links

Section 508, §1194.22(m): 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).

Forms

Section 508, §1194.22(n): 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.

Skip Navigation Links

Section 508, §1194.22(o): A method shall be provided that permits users to skip repetitive navigation links.

Timed Responses

Section 508, §1194.22(p): When a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required.

WCAG 1.0 Priority 1 Differences

There are four Priority 1 checkpoints of the Web Content Accessibility Guidelines (WCAG 1.0) that are not addressed by Section 508.

WCAG 1.0 Priority 1 Differences
Topic:	WCAG 1.0:
Auditory Descriptions:	1.3
Dynamic Content Update:	6.2
Applet and Script Alternatives:	6.3
Clear Language:	14.1

Text of WCAG 1.0 Priority 1 Differences

Auditory Descriptions

WCAG 1.0, Checkpoint 1.3: Until user agents can automatically read aloud the text equivalent of a visual track, provide an auditory description of the important information of the visual track of a multimedia presentation.

Dynamic Content Update

WCAG 1.0, Checkpoint 6.2: Ensure that equivalents for dynamic content are updated when the dynamic content changes.

Applet and Script Alternatives

WCAG 1.0, Checkpoint 6.3: Ensure that pages are usable when scripts, applets, or other programmatic objects are turned off or not supported. If this is not possible, provide equivalent information on an alternative accessible page.

Clear Language

WCAG 1.0, Checkpoint 14.1: Use the clearest and simplest language appropriate for a site's content.