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[xhtml2] Conflict between HTTP and XHTML 2.0 about mimetype

From: <karl@w3.org>
Date: Thu, 17 Aug 2006 03:27:33 -0000
To: www-html-editor@w3.org
Message-Id: <20060817032738.2B6974F54F@homer.w3.org>

Hi,
This is a QA Review comment for "XHTML 2.0"
http://www.w3.org/TR/2006/WD-xhtml2-20060726/
2006-07-26
8th WD

About http://www.w3.org/TR/2006/WD-xhtml2-20060726/mod-embedding.html#adef_embedding_srctype

In 18. XHTML Embedding Attributes Module, the specification says:

	"srctype = ContentTypes
    This attribute specifies the allowable content 
	types of the resource referenced by the relevant src URI."

no MUST, no REQUIRED, it doesn't specify the mandatoriness of the value. Though in the *informative* introduction:

	[[[
	Type: in HTML 4, the srctype attribute when referring 
	to an external resource was purely a hint to the user 
	agent. In XHTML 2 it is no longer a hint, but specifies 
	the type(s) of resource the user agent must accept.
	]]]
	-- XHTML 2.0 - Introduction
	http://www.w3.org/TR/2006/WD-xhtml2-20060726/introduction.html#backCompat
	Wed, 26 Jul 2006 20:04:35 GMT

Beside the fact that "srctype" doesn't exist in HTML 4, you meant one of the type attributes like for example
	http://www.w3.org/TR/html4/struct/objects.html#adef-type-OBJECT

It is in conflict with 
	- CHIPS - Common HTTP Implementation Problems
	  http://www.w3.org/TR/chips
	- CUAP - Common User Agent Problems
	  http://www.w3.org/TR/cuap
	- TAG findings - Mime Respect
	  http://www.w3.org/2001/tag/doc/mime-respect.html#metadata-hints
	  "Specifications MUST NOT work against the Web architecture 
	  by requiring or suggesting that a recipient override 
	  authoritative metadata without user consent."
	- HTTP 1.1
	  http://www.iana.org/rfc/rfc2616
	
and THEN in conflict with XHTML 2.0 User Agent Conformance, which says

	"When the user agent claims to support facilities defined 
	within this specification or required by this specification 
	through normative reference, it must do so in ways consistent 
	with the facilities' definition."
	http://www.w3.org/TR/2006/WD-xhtml2-20060726/conformance.html#s_conform_user_agent

	HTTP has precedence over markup languages.
	
	[[[
	Any HTTP/1.1 message containing an entity-body SHOULD include a
	Content-Type header field defining the media type of that body. If
	and only if the media type is not given by a Content-Type field, the
	recipient MAY attempt to guess the media type via inspection of its
	content and/or the name extension(s) of the URI used to identify the
	resource. If the media type remains unknown, the recipient SHOULD
	treat it as type "application/octet-stream"
	]]]
    -- 7.2.1 Type
    http://www.rfc-editor.org/rfc/rfc2616.txt




-- 
Karl Dubost - http://www.w3.org/People/karl/
W3C Conformance Manager, QA Activity Lead
   QA Weblog - http://www.w3.org/QA/
      *** Be Strict To Be Cool ***
Received on Thursday, 17 August 2006 03:29:16 GMT

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