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Re: Requesting a revision of RFC3023

From: Tim Bray <tbray@textuality.com>
Date: Thu, 18 Sep 2003 09:37:50 -0700
Message-ID: <3F69DF5E.3000102@textuality.com>
To: Bjoern Hoehrmann <derhoermi@gmx.net>
Cc: ietf-xml-mime@imc.org, WWW-Tag <www-tag@w3.org>

Bjoern Hoehrmann wrote:

> The charset parameter does not work as web servers or web server
> configurations often do not allow content providers to setup this
> parameter. In general, technical solutions should either work
> automagically behind the scene or be visible to those who need to
> be aware; HTTP headers are invisible to most content providers so
> I doubt that this is an architecturally-sound position.

Agreed, which is another of the advantages of XML, since it doesn't need 
a charset parameter.  You are right about the shortcomings of the 
charset parameter but for the moment it's the best tool we have.

>>I agree, but for XML formats, I still think the charset parameter is 
>>actively harmful and should be deprecated or even forbidden.
> 
> Deprecating something useful just because it could cause trouble when
> used improperly does not make sense to me.

The argument is precisely is that it is not in the slightest useful. 
Please read appendix F to the XML specification.  Then please suggest a 
plausible scenario in which an XML instance unaccompanied by a charset 
parameter can cause breakage.  You'll have to work hard.  Then suggest a 
dozen ways in which deployed software is known to get the charset wrong. 
  You'll have no trouble.  Given that Web Architecture says that the 
charset takes precedence *if provided*, and given that this can add no 
useful information and can easily cause breakage if (as is known to 
happen) it is wrong, there is normally no good reason to provide a 
charset parameter for a media type which is known to be XML.

Francois Yergeau managed to dream up a couple of scnenarios where you 
might want a charset with XML, but they were somewhere on the border 
between obscure and bad practice (as I'm sure Francois would agree).

To put it another way, quoting Larry Wall: "An XML document knows what 
encoding it's in."
-- 
Cheers, Tim Bray
         (ongoing fragmented essay: http://www.tbray.org/ongoing/)
Received on Thursday, 18 September 2003 12:37:58 GMT

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