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Re: WCAG 1.0 - Checkpoints 11.2 and 3.7

From: David Woolley <david@djwhome.demon.co.uk>
Date: Fri, 20 Oct 2006 09:05:04 +0100 (BST)
Message-Id: <200610200805.k9K854S04483@djwhome.demon.co.uk>
To: w3c-wai-ig@w3.org

> it mean that pages must successfully pass the W3C Markup Validation Service
> (http://validator.w3.org/) according to the used DOCTYPE ?

That's one way of testing compliance to the formal grammar, for
HTML documents.  Note that, subject to discussion in other threads on
consensus, I believe the consensus is that it is permissible to use system
identifiers in the DOCTYPE, and therefore provide your own formal grammar
(unfortunately, I don't think that Microsoft have published theirs for a
very long time).  Also, at least at one time, validator.w3.org wouldn't
accept relative system URLs, but you wouldn't fail this rule because of
a failure in the validator.

In practice, for HTML based languages, you would have to further ensure
that they didn't use any of the SGML features permitted by the grammar
but not supported by normal browsers.

If you were serving XHTML as text/html, you would also need to conform
to the Appendix C rules, even though they are not in the formal grammar
(I do not advise serving XHTML as text/html, although it is currently
very fashionable).

You may also want to consider validating against a more restrictive
grammar, e.g. by making optional tags be required, but publishing
with a DOCTYPE referencing a W3C standard superset grammar.

I'm offline at the moment, so can't easily check the section numbers.
Is the other reference to using W3C technologies.  I would certainly
say that, to be compliant, you should not depend on embed working,
even if you do provide an IE specific DTD.  embed is a particular problem,
but I think it would be reasonable to add in proprietary attributes,
with a DTD that permits them, as long as they don't convey signficant
information that could be carried using just standard HTML.

Conformance to formal grammars is an issue because:

- many, probably most, web pages have structural violations of the grammar
  (overlapping or unclosed elements, elements in forbidden places,
  missing required elements - most HTML email, like yours, is missing
  the required TITLE element, but that is at the mild end of the scale
  of what is common);

- the use of proprietary elements and attributes prevents other browsers
  properly handling the page.

Conformance to the grammar isn't enough, e.g., apart from the missing TITLE
element, your email is probably grammatically correct, but by essentially
just using DIV and FONT, it is still very bad HTML.
Received on Friday, 20 October 2006 08:58:07 UTC

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