longdesc URLs and RDFa

There is a debate in the HTMLwg about the longdesc attribute. And in 
that debate, the thought has surfaced that @longdesc,

	<img src="*" longdesc="long.html" alt="short description" />

is simply a *shorthand notation* for this (hypothetical) micro format

	<a href="long.html" rel="longdesc">	
		<img src="*" alt="short description" />
	</a>

This has resulted in an attempt to register the 'longdesc' as link 
relation. [1] Simultaneously, a search for a better documentation of 
implementations of @longdesc has been (re)started. And in that context, 
I raised a question about RDFa and @longdesc. [2]

	Observation 1: The XHTML+RDFa DOCTYPE supports the @longdesc 
attribute. 
	Observation 2: Mark Birbeck states in his 'Introduction to RDFa' 
article that «The @rel and @href attributes are no longer confined to 
the a and link elements, but can also be used on img to indicate a 
relationship between the image and some other item.» [3]
	Observation 3: A longdesc link indicates a relation between a short 
description and a long description. (See the quotes from HTML4 provided 
in [1]: 'link to long description (complements alt)' and 'link to long 
description (complements title)'.)

Questions: Would it not be logical if RDFa treated the @longdesc link 
as a semantic link - e.g. equivalent to the micro format I described 
above? What needs to be added in order to make this happen?

[1] 
http://www.ietf.org/mail-archive/web/link-relations/current/msg00047.html
[2] http://lists.w3.org/Archives/Public/public-html/2010Aug/0140
[3] http://www.alistapart.com/articles/introduction-to-rdfa/
-- 
leif halvard silli

Received on Saturday, 14 August 2010 02:59:02 UTC