W3C Web Accessibility Initiative

Requirements for WCAG 2.0

W3C Working Draft 21 April 2006

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Gregg Vanderheiden, Trace Center, University of Wisconsin-Madison
John Slatin, Accessibility Institute
Wendy Chisholm, W3C


This document outlines the requirements that the Web Content Accessibility Guidelines Working Group (WCAG WG) has set for development of Web Content Accessibility Guidelines 2.0. These requirements are based on feedback from the use of WCAG 1.0 and will be used to determine if the WCAG WG has met its goals as WCAG 2.0 advances through the W3C Recommendation Track Process.

Status of this document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

Requirements for WCAG 2.0 is being updated at this time to reflect the current assumptions that have driven the development of WCAG 2.0. (Previous version published April 2002).

Please send comments to public-comments-wcag20@w3.org. The archives for this list are publicly available. Archives of the WCAG WG mailing list discussions are also publicly available.

Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

This document has been produced as part of the W3C Web Accessibility Initiative (WAI). The goals of the WCAG WG are discussed in the WCAG Working Group charter. The WCAG WG is part of the WAI Technical Activity.


Web Content Accessibility Guidelines 1.0 (WCAG 1.0) explains how to make Web content accessible to people with disabilities. It was written for Web content developers (page authors and site designers) and developers of authoring tools. The primary goal of WCAG 1.0 is to promote accessibility. However, following the guidelines in WCAG 1.0 will also make Web content more available to all users.

Since the release of WCAG 1.0 as a W3C Recommendation in May 1999, the WCAG WG has received feedback about the usability, understandability, and applicability of the suite of documents. This feedback is driving the development of WCAG 2.0 and is captured as the Requirements for WCAG 2.0 (this document).

The primary goal of WCAG 2.0 is the same as 1.0: to promote accessibility of Web content. Additional goals discussed in this document are:

  1. Ensure that requirements may be applied across technologies
  2. Ensure that the conformance requirements are clear
  3. Design deliverables with ease of use in mind
  4. Write to a more diverse audience
  5. Clearly identify who benefits from accessible content
  6. Ensure that the revision is "backwards and forward compatible"

1. Ensure that requirements may be applied across technologies

WCAG 1.0 was written primarily for HTML documents. Authors trying to apply WCAG 1.0 to XML applications have had difficulty. Thus, WCAG 2.0 should be applicable across technologies such as:

WCAG 2.0 requirements should be expressed in generic terms so that they may apply to more than one markup language or content format.

2. Ensure that the conformance requirements are clear

WCAG 2.0 must clearly specify the minimal requirements necessary for conformance. Each requirement must be verifiable. The WCAG WG will provide resources to help readers evaluate conformance, such as success criteria, sufficient techniques, and sample content.

The deliverables must:

3. Design deliverables with ease of use in mind

The WCAG WG will attempt to make the structure of the deliverables as simple and easy to use as possible. In designing the usability of the deliverables, the WCAG WG will consult the results of the WAI Site Redesign Task Force usability testing and discuss the design with representatives of the EOWG.

4. Write to a more diverse audience

WCAG 2.0 deliverables must address the needs of a variety of readers, including people who wish to:

The number, length, and organization of the deliverables should address the different needs of these readers. The language used in the deliverables should be as easy as possible to translate into other languages. As part of ensuring that the diverse needs of readers are met, the WG will work with the Education and Outreach Working Group.

5. Clearly identify who benefits from accessible content

6. Ensure that the revision is "backwards and forward compatible"

A number of other documents and software, such as specifications, evaluation tools, authoring tools, and government and organizational policies, reference WCAG 1.0. Therefore, WCAG 2.0 should introduce as few changes as possible to the definition of accessible Web content. At the same time, WCAG 2.0 should be designed to work with emerging and future techologies as much as is possbile.