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Re: Images and alternative text

From: Leif Halvard Silli <lhs@malform.no>
Date: Mon, 11 Aug 2008 18:42:13 +0200
Message-ID: <48A06BE5.60105@malform.no>
To: Robert J Burns <rob@robburns.com>
CC: Smylers <Smylers@stripey.com>, "public-html@w3.org" <public-html@w3.org>

Robert J Burns 2008-08-11 13.26:

> On Aug 10, 2008, at 3:22 PM, Smylers wrote:
>> James Graham writes:

>>> [...] an alternative proposal with similar semantics [...]
>>> a boolean attribute to image called no-text-equivalent
>>> [...]

@no-text-equivalent is proposed as a boolean. Wheras alt="{photo}" 
presents and textual alternative to the lacking textual 
equivalent. Thus, they are not similar.

> Both suggestions (the separate attribute and the special syntax for the 
> alt attribute) were both discussed at length long before Ian made the 
> suggestion. An obvious contender for the former is the role attribute 
> (requiring it for all non-text media). For the latter, I think the 
> problems with legacy UAs are too great to take such a proposal seriously 
> anymore.

Regarding obvious contender: a role="no-text-equivalent" would 
probably not be so interesting to have. I think @role rejects the 
idea behind @no-text-equivalent.

As for role="photo" vs. alt="{photo}, the latter is intended to be 
read by the user. Wheras @role needs interpretation by an UA 
before eventual presentation to the user. @role therefore 
"suffers" from a limited set of values, in English. Thus for @role 
there seems to be an UA localisation problem.

Regarding @tagged (see my previous reply and the examples below): 
@tagged is basically the same idea that Ian has presented. Without 
his syntax and without any clashes with {TeX} or other syntaxes.

Ex. 1: <img src=src alt="photo" tagged >
Ex. 2: <img src=src alt="Mum and dad." tagged="photo" >

@tagged might look similar to @role. Therefore I want to describe 
the differences: It seems to me that @role speaks about the entire 
IMG element. Wheras both Ian's propoisal as well as @tagged are 
only meant to say something about how the content of @alt should 
be interpreted.

Thus, there is nothing which prevents us from having both @role 
and @tagged simultaneously. Though it would of course be possible 
to have role="tagged" to say the same thing as the boolean variant 
of @tagged.

As long as @tagged and/or Ians curly brackets syntax only speak 
about how the content of @alt should be interpreted, then the 
question of requiring @role on all non-text media elements becomes 
a different question. (Unless, of course, we go for role=tagged.)

[1] http://www.w3.org/TR/xhtml-role/
leif halvard silli
Received on Monday, 11 August 2008 16:43:02 UTC

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