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Re: XHTML 2.0 User Agent Conformance

From: Jim Ley <jim@jibbering.com>
Date: Fri, 31 Oct 2003 11:03:09 -0000
To: www-html@w3.org
Message-ID: <bntfk0$6e9$1@sea.gmane.org>

"Lachlan Hunt" <lhunt07@postoffice.csu.edu.au> wrote in message

>   Due to the huge problem of authors marking up pages with invalid
> (X)HTML in the past, because of the attitude: 'if it displays well, I've
> written it well',

I do not believe this is the reason why people have problems authoring valid
markup, it's certainly a reason why authors can not spend the extra time
working at it, but it is not the reason for the invalid mark-up in the first

> I think it would be wise to state in the conformance
> section of XHTML2 that user agents must process a page as strictly as a
> general XML document.

XHTML 1.0 and 1.1 already has this ridiculous assertion AIUI.

>   ie. displaying an error message if the markup is invalid,

This is a very bad idea, users do not need to be shown the mechanics,
they're interested in getting the content.  User Agents have bugs, if a UA
has a bug which leads it to think my valid document is invalid and displays
error or fails to render the document - I've done nothing wrong, and there
is nothing I can do to fix it, but my clients and customers get a bad
impression of me.

Also XHTML 1.0 has shown the importance of the flexible rendering to allow
for user agents and Mark Up Language recommendation writers to develop new
standards which are compatible with what has gone before - XHTML 1.0 can
only be rendered by todays UA's because they were fault tolerant.  If we
remove fault tolerance we lose that ability to correct the errors in our ML.

What happens with an errata which fixes an error in the original XHTML 2.0
specification, UA's pre-Errata would handle a document different from UA's
post-Errata, this would almost certainly not be sustainable.

>  Also, it might start making browser vendors ensure that
> they, themselves, conform to the specs, as so many are guilty of not
> doing in the past.

Have you considered the cost of shipping a conformant browser?  The number
of hours in Mozilla are huge, yet they've still not delivered a conformant
browser, and all software has bugs, which are likely to impact negatively.

A conformance requirement on servers which requires them to serve valid
documents to use the relevant mime-type for them, I'd support, that imposes
no burden on clients, and authors will know instantly if there are any bugs
in their server which require fixing. (They'll only be using a single
server, rather than the situation where they're serving it to a potentially
infinite number of clients)


Received on Friday, 31 October 2003 06:04:49 UTC

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