There are two major Web standards used today to define accessible Web content for people with disabilities: W3C Web Content Accessibility Guidelines version 1.0 (WCAG 1.0) (link resides outside of ibm.com) and
US Section 508 of the Rehabilitation Act of 1973 (link resides outside of ibm.com). (See note 1). WCAG 1.0, developed by a working group in an open consensus process, was the first to be published in May 1999. US Section 508, finalized in December 2000, was developed by the US Access Board based on recommendations from a committee composed of academics, disability advocates and industry representatives. US federal government agencies are required by law to make their websites comply with the requirements in Section 508. Many US state governments also have laws or policies that require their websites to meet the Section 508 requirements. Outside the US, however, most governments with accessibility policies refer to WCAG 1.0 as their accessibility standard.
IBM has a long history of accessibility and early versions of the IBM Web Accessibility Checklist actually predated both of these standards. As a supplier to the federal government over time, IBM aligned its checklist with the US Section 508 standard. Since many of the Section 508 requirements are equivalent to WCAG 1.0 requirements, the IBM checklist is also aligned with a subset of WCAG 1.0 requirements.
IBM provides these comparisons of the two standards and IBM's guidelines to help web site designers navigate these similar, but not identical standards. Table 1 illustrates the IBM, US Section 508, and WCAG 1.0 checkpoints that are functionally equivalent. (See note 2). Table 2 illustrates where the IBM Web Accessibility and US Section 508 checkpoints differ from WCAG 1.0 checkpoints.
| Check point Number | IBM Web Checkpoint Description | Section 508 | WCAG 1.0 Guideline |
|---|---|---|---|
| 1 | Use the alt="text" attribute to provide text equivalents for images. Use alt="" for images that do not convey important information or convey redundant information. | 1194.22 (a) A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content). | 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. [Priority 1] |
| 2 | Use client-side image maps with alternative text for image map hot spots. If a server-side map is needed, provide equivalent text links. | 1194.22 (e) Redundant text links shall be provided for each active region of a server-side image map. | 1.2 Provide redundant text links for each active region of a server-side image map. [Priority 1] |
| 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. | 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. [Priority 1] | ||
| 3 | Summarize the content of each graph and chart, or use the longdesc attribute to link to the description or data. | 1194.22 (a) A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content). | 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. [Priority 1] |
| 9 | Provide a title for each FRAME element and frame page. Provide an accessible source for each frame. | 1194.22 (i) Frames shall be titled with text that facilitates frame identification and navigation. | 12.1 Title each frame to facilitate frame identification and navigation. [Priority 1] |
| 10 | Use the TH element to mark up table heading cells. Use the headers attribute on cells of complex data tables. | 1194.22 (g) Row and column headers shall be identified for data tables. | 5.1 For data tables, identify row and column headers. [Priority 1] |
| 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. | 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. [Priority 1] | ||
| 11 | Web pages should be readable without requiring style sheets. | 1194.22 (d) Documents shall be organized so they are readable without requiring an associated style sheet. | 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. [Priority 1] |
| 12 | Ensure that all information conveyed with color is also conveyed in the absence of color. | 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. | 2.1 Ensure that all information conveyed with color is also available without color, for example from context or markup. [Priority 1] |
| 15 | If accessibility cannot be accomplished in any other way, provide a text-only page with equivalent information or functionality. Update the content of the text-only page whenever the primary page changes. | 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. | 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. [Priority 1] |
| 16 | Test the accessibility using available tools. | Implied | Implied |
| Check point Number | IBM Web Checkpoint Description | Section 508 | WCAG 1.0 Guideline |
|---|---|---|---|
| 4 | Provide captions or transcripts of important audio content. Provide transcripts or audio descriptions of important video content. (See Note 3) |
1194.22 (b) Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation. | 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. [Priority 1] |
| 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. [Priority 1] |
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| 5 | Ensure the functionality of scripts is keyboard accessible. If the content affected by scripting is not accessible, provide an alternative. | 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 ready by assistive technology. | 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. [Priority 1] |
| 6.2 Ensure that equivalents for dynamic content are updated when the dynamic content changes. | |||
| 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. [Priority 1] | |||
| 6.4 For scripts and applets, ensure that event handlers are input device-independent. [Priority 2] |
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| 9.3 For scripts, specify logical event handlers rather than device-dependent event handlers. [Priority 2] |
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| 6 | When an applet, plug-in or other application is required to be present, provide a link to one that is directly accessible, or provide alternate content for those which are not directly accessible. | 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). | 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. [Priority 1] |
| 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. [Priority 1] |
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| 6.4 For scripts and applets, ensure that event handlers are input device-independent. [Priority 2] |
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| 7 | Make forms accessible to assistive technology. | 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. | 12.4 Associate labels explicitly with their controls. [Priority 2] 10.2 Until user agents support explicit associations between labels and form controls, for all form controls with implicitly associated labels, ensure that the label is properly positioned. [Priority 2] |
| 8 | Provide methods for skipping over navigation links to get to main content of page. | 1194.22 (o)A method shall be provided that permits users to skip repetitive navigation links. | 13.6 Group related links, identify the group (for user agents), and, until user agents do so, provide a way to bypass the group. [Priority 3] |
| 13 | Avoid causing content to blink, flicker, or move. | 1194.22 (j) Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2Hz and lower than 55Hz. | 7.1 Until user agents allow users to control flickering, avoid causing the screen to flicker. [Priority 1] (See note 4) |
| 7.2 Until user agents allow users to control blinking, avoid causing content to blink (i.e., change presentation at a regular rate, such as turning on and off). [Priority 2] |
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| 7.3 Until user agents allow users to freeze moving content, avoid movement in pages. [Priority 2] |
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| 14 | When a timed response is required, alert the user, and give sufficient time to indicate more time is required. | 1194.22 (p) When a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required. | 7.4 Until user agents provide the ability to stop the refresh, do not create periodically auto-refreshing pages. [Priority 2] |
| 7.5 Until user agents provide the ability to stop auto-redirect, do not use markup to redirect pages automatically. Instead, configure the server to perform redirects. [Priority 2] |
The following WCAG 1.0 priority 1 checkpoints are not included in either the IBM Web Accessibility Checklist or the US Section 508 requirements.
- 4.1 Clearly identify changes in the natural language of a document's text and any text equivalents.(e.g. captions)
- 14.1 Use the clearest and simplest language appropriate for a site's content
In addition, WCAG 1.0 contains many priority 2 and 3 checkpoints that are not required by either IBM or Section 508.
1Detailed in 36 Code of Federal Regulations Section 1194.22 Web-based intranet and internet information and applications
2 (See the Note to §1194.22 located after §1194.22 (p) in the US Section 508 Technical Standards.)
3 Section 508 and WCAG 1.0 requirements related to text equivalents for multimedia are equivalent, however, the IBM checklist does allow for a transcript in certain cases.
4 The Note to §1194.22 located after §1194.22 (p) in the US Section 508 Technical Standards, indicates that §1194.22 (j) is equivalent to WCAG 1.0 checkpoint 7.1. It is IBM’s interpretation, however, that these are not equivalent as Section 508 allows flickering as long as it does not fall within a certain range. WCAG 1.0, however, does not allow any flickering at all.