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[CTG] Draft 2008-11-07 / http-equiv

From: Eduardo Casais <casays@yahoo.com>
Date: Tue, 11 Nov 2008 01:32:28 -0800 (PST)
To: public-bpwg-ct@w3.org
Message-ID: <249350.71590.qm@web45004.mail.sp1.yahoo.com>


Section 4.2 states:
	"In the following, proxies must check for 
	the presence of equivalent <meta http-equiv> 
	elements in HTML content, if the relevant 
	HTTP header is not present."

This comes too short, as XHTML and WML content may
contain such a meta-tag as well. In the case of WML,
the presence of http-equiv attributes and their 
processing is actually specified in the corresponding
standards (notably WAP-191-WML 19 February 2000, and
WAP-WML 16 June 1999).

b)	Page components

The http-equiv meta-tag is necessary because there are
situations where application developers cannot tailor
the HTTP header returned by the WWW server (e.g. shared
hosting). However, it must be clear that the meta-tag,
and the HTTP header field as well, apply to all components
of the page -- i.e. including images, style sheets, scripts,
and other dependent content.

In effect:
1. It does not make much sense not to transform the markup,
but to transform its components.
2. Most of the dependent content (in fact everything 
excluding HTML, XHTML, WML markup) has no way of 
expressing the directive no-transform with a meta-tag 
(e.g. a GIF image or a ringing tone).
3. Much of these dependent components may not be identifiable
as mobile-optimized independently; hence, an HTTP request
accessing them after loading their enclosing markup may not
provide sufficient context for applying the heuristics in
the appendix (e.g. GIF/PNG/JPEG images).

a)	Link element

Section 4.2.7 addresses the alternate "handheld" representation
for HTML markup. This is restrictive:

1. This should apply to XHTML as well.
2. Ignored are external style sheets.

In the case of external style sheets, it is pretty clear that
those declared as 

<link rel="stylesheet" type="text/css" href="..." media="all"/>
<link rel="stylesheet" type="text/css" href="..." media="handheld"/>

also refer to mobile-compatible, resp. mobile-optimized ones,
and should be handled accordingly.


Received on Tuesday, 11 November 2008 09:34:06 UTC

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