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RE: DTD etc

From: Nick Kew <nick@webthing.com>
Date: Thu, 12 Sep 2002 19:03:17 +0100 (BST)
To: John Foliot - bytown internet <foliot@bytowninternet.com>
cc: w3c-wai-ig@w3.org
Message-ID: <Pine.LNX.4.21.0209121832250.1473-100000@jarl.webthing.com>

On Thu, 12 Sep 2002, John Foliot - bytown internet wrote:

> Might I add that if you *must* adhere to W3C Priority 2 Guidelines (ie:
> interpret as Standards, as is the situation here in Canada), then the DTD
> *MUST* be present, per the HTML Specifications (http://www.w3.org/TR/html).

Pedantic point: you mean the FPI.

> The DTD has been made mandatory in the spec since HTML 3.2 was finalized in
> 1997;  Html 4.01 has been "stable" since 1999.
> WCAG Priority 2, 3.2 states: "Create documents that validate to published
> formal grammars."  Thus, to satisfy this requirement, your document must
> contain the DTD - as that is part of the published formal grammar. (I didn't
> write it, I just read it.)

That's logically correct.  Though it's also worth pointing out that at
the time the WCAG was written, all the online validators would permit
omission of the FPI, and would validate to a default doctype in the
absence of an explicit one.

The underlying point is of course that the markup should be correct.
That too is problematic.  Valet is stricter about validation than other
accessibility tools, and delivers a straight fail on invalid markup
when evaluating at AA or AAA.  This leads to many users finding it too
strict, and preferring something to reassure them:-(

> Most user agents today will interpret HTML with or without the DTD, so from
> a practical "will it still work without" perspective, it's generally not an
> issue.  When people ask me why they should be concerned with the inclusion
> of the DTD, I usually use the following analogies:

I would apply a simpler test: they must validate, and they can't validate
without it (actually in SGML terms they can, but HTML imposes additional

OTOH I wouldn't quarrel with your answers.

> So leaving it out (IMHO) courts disaster... it's like driving without the
> seatbelt.

Are you familiar with my page at

Nick Kew
Received on Thursday, 12 September 2002 14:03:25 UTC

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