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RE: verbose image descriptor requirements

From: John Foliot <jfoliot@stanford.edu>
Date: Thu, 12 Aug 2010 20:24:09 -0700 (PDT)
To: "'Gregory J. Rosmaita'" <oedipus@hicom.net>, <public-html-a11y@w3.org>, <wai-xtech@w3.org>
Message-ID: <035501cb3a96$fac2b1c0$f0481540$@edu>
For what it’s worth…

One piece of information that came to light this week is that Oracle might 
have a policy that mandates the use of @longdesc internally. Sam Ruby has 
indicated that if this is the case, it might be grounds to re-open the 

To that end, I have reached out to Peter Wallack, who is Accessibility 
Program Director at Oracle (thanks again LinkedIn) – I have met Peter on a 
few occasions, and while not chummy-chummy he knows me and what I do. He is 
currently on vacation (according to his autoresponder), and so I do not 
anticipate hearing from him before next Monday, but thought I would bring 
interested parties up to date.



From: public-html-a11y-request@w3.org 
[mailto:public-html-a11y-request@w3.org] On Behalf Of Gregory J. Rosmaita
Sent: Thursday, August 12, 2010 5:42 PM
To: public-html-a11y@w3.org; wai-xtech@w3.org
Subject: verbose image descriptor requirements


so that we are all working towards the same end (no matter the specific
means) i have put up a list of requirements and some thoughts about how
they can be achieved using the toolkit currently at the disposal of


i have attempted to keep the requirements few, clear and simple, but
if you have one i haven't listed or have a terser, clearer means of
expressing any of the requirements, please do so...  as of 2010-08-13
0037 UTC the page contained the following content:

Verbose (As Long As Necessary) Descriptor Requirements

1. A way to reference a specific set of structured content, internal
  (enhanced describedby model) or external (HTML4 longdesc model)
  to the document containing the described image;

2. A way to inform all users that the descriptive content is

3. A device independent way for all users to access the descriptive

4. An explicit provision that accessing descriptive content, whether
  internal or external to the document containing the image, does
  NOT take the user away from the user's position in the document
  containing the image where the verbose descriptor was invoked;

5. A way to provide user control over exposition of the descriptor
  so that rendering of the image and its description is not an
  either/or proposition;

Satisfying These Requirements for HTML5

Question: are these options or steps?

* retain support for longdesc; allow for exposition of longdesc inline
 as well as for simultaneous exposition of both the image and its
 description (useful for those with very limited viewports or users
 with cognative issues, who may need a description's guide to assist
 in the user's understanding of the image being described);
     * advantage: 2 major browsers already support longdesc natively
       and are expected to continue to do so as part of their support
       for HTML4x;

* add support for aria-describedby and deprecate longdesc in HTML5;
     * drawback: aria-describedby is currently limited to text that
       appears in the same document as the image being described;
     * drawback: The content associated using aria-describedby as
       currently implemented, is limited to unstructured text;

* add support for external references and structured text to the
 aria-describedby attribute in HTML5 and deprecate longdesc;

Related Resources
[1] HTML 5 Issue: Image Equivalent Content (HTML WG Wiki page)

[2] HTML WG Issue-130 (longdesc)

[3] Chairs' decision on HTML WG Issue-130 (longdesc)

[3.1] cover letter for Chairs' decision on HTML WG Issue-130 (longdesc)
Received on Friday, 13 August 2010 03:24:44 UTC

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