Guideline 4.1 Background and Proposal

WCAG WG F2F, 18 October 2005

Wendy Chisholm

W3C/WAI

Background

Summarized from: Validity and Accessibility

• 5 May 1999: WCAG 1.0
  Checkpoint 3.2 "Create documents that validate to published formal grammars" Priority 2.
• Early 1999:WAI Quicktips
  "Check your work. Validate. Use tools, checklist, and guidelines at http://www.w3.org/TR/WCAG"
• 25 January 2001: First WCAG 2.0 Working Draft
  "markup conforms to the validity tests of the language (whether it be conforming to a schema, DTD, or other tests described in the specification)." No priorities.
• 14 June 2005: Guideline 4.1 Level 2 SC1 proposal:
  "Except where the author has documented that a specification was violated for user agent compatibility (including compatibility with assistive technology), the content has:
  1. passed validity tests for the version of the technology in use (whether it be conforming to a schema, Document Type Definition (DTD), or other tests described in the specification), and
  2. used technology features as defined in the specification."
• 14 June 2005, cont: Action to investigate L1 SC to address "well-formedness" in HTML/SGML, Flash, PDF
• 15 June 2005 (ongoing): Spirited discussion
  (WCAG WG mailing list, Juicy Studio, bestkungfu, WaSP Buzz, etc.).
• 30 June 2005: updated Working Draft of WCAG 2.0.
  All success criteria for Guideline 4.1 replaced with an ednote.

Since June

• Discussions with W3C Staff (Tim, et al), editors
• Analysis of common validity errors impact accessibility
  (test examples)
• Goal:
  • In-sync with W3C message
  • Determining what is essential for accessibility
  • Avoiding enforcement of W3C technologies ("WCAG as a trojan horse")

More About Custom DTDs

More About Custom DTDs - W3C QA Group

The proper use of the shared semantics of a standard markup language empowers me as a web author, and since I know that validation is one practical way of getting close to that goal, therefore I validate my web documents.

It is important to remain conscious, however, that validity alone is not a guarantee of compliance, and even further from being a guarantee of quality.

...Nothing in a DTD, for instance, can enforce that the content of the lang attribute must be a language code from RFC1766"

Latest proposal

• Guide: "Delivery units can be parsed unambiguously."
• Benefits of this approach
  • use validators to determine well-formedness, unique ids
  • doesn't "outlaw" all validity errors
• Nothing proposed at Level 2 to focus discussion on this approach
• Presented to W3C team on 13 October. No major concerns raised.