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Re: Baselines: how specific?

From: Gez Lemon <gez.lemon@gmail.com>
Date: Tue, 14 Mar 2006 18:26:49 +0000
Message-ID: <e2a28a920603141026o747ca4f5l@mail.gmail.com>
To: w3c-wai-gl@w3.org

Hi Christophe,

A list of technologies is a simple binary representation that does
not do justice to the reality of incomplete implementations by
user agents.

That's very true, and quite ironic given that UAAG couldn't be used
because no user-agents adhere to it. It gets difficult, as we could
easily end up with a situation where HTML couldn't be included as a
technology because it's not properly supported.

Some websites that puts HTML 4.01 in their baseline will
assume that every feature is supported, while others will assume that
object, link, longdesc, etc are not adequately supported by the user
agents of a significant percentage of their visitors. This means that
some websites will use fall-back techniques such as 'embed', while others
will not.

This takes me to another aspect of my original question: if websites
use 'embed' or other non-standard features, shouldn't that be part of the
baseline also? Just specifying 'HTML 4.01' in the baseline would be

Some good points, but how would you specify a non-technology in the
baseline? Putting, "non-standard HTML" wouldn't be acceptable. Maybe a
better approach would be to assume that all features of a technology
are supported, and introduce a "Repair Techniques" or similar section,
where authors can document how they overcome known shortcomings in

The third aspect of my question is whether a baseline should specify
which version or profile of a technology is assumed. For example, is it
sufficient to say "HTML 4.01" or is it necessary to say "HTML 4.01 Strict"?
(I'm in favour of the latter, more specific, approach.)

I'm also in favour of the latter, but can't help thinking that the
extra information isn't really useful to anyone in terms of a
conformance claim. If structure, presentation, and behaviour have been
separated (a requirement of the guidelines), is there any benefit in
knowing whether HTML as a technology is transitional or strict?

Some W3C technologies have been "modularized": is it necessary to
 specify which modules are assumed to be supported? I think it is.
  The question about modularizaton also throws a different light on the question
 of specifying whether specific features (e.g. object in HTML) can be
 mentioned: after all, modules are collections of such features.

Modules can also packaged, and I would personally prefer the
technologies in the baseline to be as succinct as possible. For
example, XHTML 1.0 is based on XHTML abstract modules [1], so I
wouldn't see the point of listing them all individually if they were
included as a collection (including other modular flavours of XML
markup languages). I can see the purpose of including individual
modules, such as XForm, but not the features of those modules.

Is it also necessary to specify which MIME types are assumed to be
supported? This is relevant when using XHTML 1.0.

Another excellent point. MIME types aren't included in the definition
of "technology", unless "data formats" covers this, but I would like
to see it included.

[1] http://www.w3.org/TR/2001/REC-xhtml-modularization-20010410/abstract_modules.html

Best regards,


Supplement your vitamins
Received on Tuesday, 14 March 2006 18:26:58 UTC

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