IBM Web Accessibility Checklist, W3C Web Content Accessibility Guidelines 2.0 (WCAG 2.0) and US Section 508.
There are two major Web standards used today to define accessible Web content for people with disabilities: W3C Web Content Accessibility Guidelines version 2.0 (WCAG 2.0) (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 2.0, developed by a working group in an open consensus process, was published in December 2008. 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 Web sites comply with the requirements in Section 508. Many US state governments also have laws or policies that require their Web sites to meet Section 508 requirements. Outside the US, however, most governments with accessibility policies refer to WCAG 2.0 as their accessibility standard.
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 2.0 checkpoints that are functionally equivalent. (See note 2). Table 2 illustrates where the IBM Web Accessibility and US Section 508 checkpoints differ from WCAG 2.0 checkpoints.
IBM Web 5.1 Checkpoint |
Section 508 Standard |
WCAG 2.0 |
1.1a: Text Alternatives: |
1194.22 (a) A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content). |
1.1.1 Non-text Content: (link resides outside of ibm.com). All non-text content that is presented to the user has a text alternative that serves the equivalent purpose, except for the situations listed below. (Level A) |
1.1b: Non-text Content |
N/A |
1.1.1 Non-text Content: (link resides outside of ibm.com) All non-text content that is presented to the user has a text alternative that serves the equivalent purpose, except for the situations listed below. (Level A) |
1.1c: Image maps: |
1194.22 (e) Redundant text links shall be provided for each active region of a server-side image map. |
N/A |
1.2a: Captions: |
1194.22 (b) Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation. |
1.2.2 Captions (Prerecorded) (link resides outside of ibm.com):. Captions are provided for all prerecorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labeled as such. (Level A) |
1.2b: Audio and Video (Prerecorded): |
1194.22 (b) Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation. |
1.2.1 Audio-only and Video-only (Prerecorded) (link resides outside of ibm.com):. For prerecorded audio-only and prerecorded video-only media, the following are true, except when the audio or video is a media alternative for text and is clearly labeled as such: (Level A) |
1.2c: Live Multimedia: |
1194.22 (b) Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation. |
1.2.4 Captions (Live) (link resides outside of ibm.com): Captions are provided for all live audio content in synchronized media. (Level AA) |
1.3a: Information and Relationships: Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text. |
N/A |
1.3.1 Info and Relationships (link resides outside of ibm.com): Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text. (Level A) |
1.3c: Meaningful Sequence When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically |
N/A |
1.3.2 Meaningful Sequence: (link resides outside of ibm.com) When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically determined. (Level A) |
1.3d: Forms: Form element labels can be programmatically determined. |
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. |
1.3.1 Info and Relationships (link resides outside of ibm.com): Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text. (Level A) |
1.3e: Tables: Table cells and relationships between cells can be programmatically determined. |
1194.22 (g) Row and column headers shall be identified for data tables. |
1.3.1 Info and Relationships (link resides outside of ibm.com): Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text. (Level A) |
1.3f: Cascading style sheets: Web pages are readable without requiring style sheets. |
1194.22 (d) Documents shall be organized so they are readable without requiring an associated style sheet. |
N/A |
1.3g: Sensory Characteristics: |
N/A |
1.3.3 Sensory Characteristics (link resides outside of ibm.com): Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, size, visual location, orientation, or sound. (Level A) |
1.4a: Use of Color: Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. |
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. |
1.4.1 Use of Color (link resides outside of ibm.com): Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. (Level A) |
1.4b: Audio Control: If any audio on a Web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume independently from the overall system volume level. |
N/A |
1.4.2 Audio Control (link resides outside of ibm.com): If any audio on a Web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume independently from the overall system volume level. (Level A) |
2.1a: Keyboard: All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints. |
N/A |
2.1.1 Keyboard (link resides outside of ibm.com): All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints. (Level A) |
2.1b: Scripts: Scripts are keyboard accessible. If the content affected by scripting is not accessible, an alternative is provided. |
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. |
2.1.1 Keyboard (link resides outside of ibm.com): All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints. (Level A) |
2.1c: Applets, plug-ins: and non-HTML content. A link is provided to a directly accessible applet, plug-in or other application. Alternate content is provided for those applets, plug-ins or other applications that 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). |
2.1.1 Keyboard (link resides outside of ibm.com): All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints. (Level A) |
2.1d: No Keyboard Trap: If keyboard focus can be moved to a component of the page using a keyboard interface, then focus can be moved away from that component using only a keyboard interface, and, if it requires more than unmodified arrow or tab keys, the user is advised of the method for moving focus away. |
N/A |
2.1.2 No Keyboard Trap (link resides outside of ibm.com): If keyboard focus can be moved to a component of the page using a keyboard interface, then focus can be moved away from that component using only a keyboard interface, and, if it requires more than unmodified arrow or tab keys or other standard exit methods, the user is advised of the method for moving focus away. (Level A) |
2.2a: Adjust time response: The user is allowed to turn off, adjust or extend all time limits that are not a real-time, essential or 20 hour exception. |
1194.22 (p) When a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required. |
2.2.1 Timing Adjustable (link resides outside of ibm.com): For each time limit that is set by the content, at least one of the following is true: (Level A) |
2.2b: Pause, Stop, Hide: The user is allowed to pause, stop, or hide moving, blinking, scrolling, or auto-updating information unless it is an essential part of an activity. |
N/A |
2.2.2 Pause, Stop, Hide (link resides outside of ibm.com): For moving, blinking, scrolling, or auto-updating information, all of the following are true: (Level A) |
2.3a: Three Flashes or Below Threshold: Web pages do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds. |
1194.22 (j) Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2Hz and lower than 55 Hz. |
2.3.1 Three Flashes or Below Threshold (link resides outside of ibm.com): Web pages do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds. (Level A) |
2.4a: Navigational features: A mechanism is available to bypass blocks of content that are repeated on multiple Web pages. |
1194.22 (o)A method shall be provided that permits users to skip repetitive navigation links |
2.4.1 Bypass Blocks (link resides outside of ibm.com): A mechanism is available to bypass blocks of content that are repeated on multiple Web pages. (Level A) |
2.4b: Skip to main content: |
|
|
2.4c: Frames: A title and an accessible frame source are provided for each frame. |
1194.22 (i) Frames shall be titled with text that facilitates frame identification and navigation. |
2.4.1 Bypass Blocks (link resides outside of ibm.com): A mechanism is available to bypass blocks of content that are repeated on multiple Web pages. (Level A) |
2.4d: Page Titles and Link Purpose: Web pages have titles that describe topic or purpose. |
N/A |
2.4.2 Page Titled (link resides outside of ibm.com): Web pages have titles that describe topic or purpose. (Level A) |
2.4e: Focus Order: If a Web page can be navigated sequentially and the navigation sequences affect meaning or operation, focusable components receive focus in an order that preserves meaning and operability. |
N/A |
2.4.3 Focus Order (link resides outside of ibm.com): If a Web page can be navigated sequentially and the navigation sequences affect meaning or operation, focusable components receive focus in an order that preserves meaning and operability. (Level A) |
2.4f: Link Purpose. The purpose of each link can be determined from the link text alone or from the link text together with its programmatically determined link context, except where the purpose of the link would be ambiguous to users in general. |
N/A |
2.4.4 Link Purpose (In Context) (link resides outside of ibm.com): |
3.1a: Language of Page: The default human language of each Web page can be programmatically determined. |
N/A |
3.1.1 Language of Page (link resides outside of ibm.com): The default human language of each Web page can be programmatically determined. (Level A) |
3.2a: On Focus: When any component receives focus, it does not initiate a change of context. |
N/A |
3.2.1 On Focus (link resides outside of ibm.com): When any component receives focus, it does not initiate a change of context. (Level A) |
3.2b: On Input: Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component. |
N/A |
3.2.2 On Input (link resides outside of ibm.com): Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component. (Level A) |
3.3a: Error Identification: If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text. |
N/A |
3.3.1 Error Identification (link resides outside of ibm.com): If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text. (Level A) |
3.3b: Labels or Instructions: Labels or instructions are provided when content requires user input. For all user interface components, the name and role can be programmatically determined, values that can be set by the user can be programmatically set, and notification of changes to these items is available to user agents, including assistive technologies. |
N/A |
3.3.2 Labels or Instructions (link resides outside of ibm.com): Labels or instructions are provided when content requires user input. (Level A) |
4.1a: Parsing: In content implemented using markup languages, elements have complete start and end tags, elements are nested according to their specifications, elements do not contain duplicate attributes, and any IDs are unique, except where the specifications allow these features. |
N/A |
4.1.1 Parsing (link resides outside of ibm.com): In content implemented using markup languages, elements have complete start and end tags, elements are nested according to their specifications, elements do not contain duplicate attributes, and any IDs are unique, except where the specifications allow these features. (Level A) Note: Start and end tags that are missing a critical character in their formation, such as a closing angle bracket or a mismatched attribute value quotation mark are not complete. |
4.1b: Name, Role, Value: For all user interface components (including but not limited to: form elements, links and components generated by scripts), the name and role can be programmatically determined; states, properties, and values that can be set by the user can be programmatically set; and notification of changes to these items is available to user agents, including assistive technologies. |
N/A |
4.1.2 Name, Role, Value (link resides outside of ibm.com): For all user interface components (including but not limited to: form elements, links and components generated by scripts), the name and role can be programmatically determined; states, properties, and values that can be set by the user can be programmatically set; and notification of changes to these items is available to user agents, including assistive technologies. (Level A) |
4.2a: Text-only page: If accessibility cannot be accomplished in any other way, a text-only page with equivalent information or functionality is provided. |
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. |
N/A |
4.2b: Accessibility-Supported Technologies Only: Use accessibility supported technologies. Any information or functionality that is implemented in technologies that are not accessibility supported must also be available via technologies that are accessibility supported. |
N/A |
All WCAG 2.0 Success Criteria are written as testable criteria for objectively determining if content satisfies them. Testing the Success Criteria would involve a combination of automated testing and human evaluation. The content should be tested by those who understand how people with different types of disabilities use the Web. Understanding Conformance (link resides outside of ibm.com). |
W3C Recommendation 11 December 2008: http://www.w3.org/TR/WCAG20/ (link resides outside of ibm.com).
Copyright 1994-2009 W3C (Massachusetts Institute of Technology, European Research Consortium for Informatics and Mathematics, Keio University), All Rights Reserved.
®2009 IBM Corporation
Last updated October 1, 2009.
1Detailed in 36 Code of Federal Regulations Section 1194.22 Web-based intranet and internet information and applications in the US Section 508 Technical Standards (link resides outside of ibm.com).
2 See the Note to §1194.22 located after §1194.22 (p) in the US Section 508 Technical Standards (link resides outside of ibm.com).
