RE: Image description extension review

Hi Chaals

 

On the call you had mentioned that longdesc pointing to an anchor on the same page is included in the HTML4 spec. I’m sorry but I’m unable to find any reference or example in HTML 4 of Longdesc referring to information (an anchor id) on the same page. Nor can I find any recommended advice to use null alt text (alt=“”) on an image that has a longdesc... 

 

Nor are there any example techniques in WCAG showing this use of longdesc or of null alt text.

http://www.w3.org/TR/2012/NOTE-WCAG20-TECHS-20120103/H45 

 

In 10 years on the WCAG team and weekly calls, I’ve never heard this use case of Longdesc discussed, nor in 14 years in the field have I ever seen it done.

 

I’m fine with the longdesc extension... but I think we either need to demonstrate that this use case exists in the real world and is in HTML4, or we have to acknowledge that it’s a new behaviour for Longdesc.  I also don’t think we should introduce null alt text for anything but decorative images... so far automated checkers rightly flag null alt text to ensure it’s purely decorative... in the future we may need to expand the use of null alt text for cases when there is another type of text alternative such as figcaption, aria-describedby, longdesc, etc.. but I don’t think such a precedence currently exists.

 

HTML4 references

http://www.w3.org/TR/REC-html40/struct/objects.html#adef-longdesc-IMG

http://www.w3.org/TR/REC-html40/struct/objects.html#adef-alt

http://www.w3.org/TR/REC-html40/appendix/notes.html#accessibility

 

 

 

Cheers

David MacDonald

 

CanAdapt Solutions Inc.

  "Enabling the Web"

 <http://www.can-adapt.com/> www.Can-Adapt.com

 

From: Charles McCathie Nevile [mailto:chaals@yandex-team.ru] 
Sent: November-15-12 9:08 PM
To: public-html-a11y@w3.org; Léonie Watson
Subject: Re: Image description extension review

 

On Fri, 09 Nov 2012 21:41:55 +0100, Léonie Watson <tink@tink.co.uk> wrote:

Hello,

 

A few thoughts, mostly editorial.

 

Mostly I've adopted or adapted your suggestions.  

 

Introduction...

 

The code examples all have null alt attributes. Could they be more practical examples?

 

Actually only one had a null value, the others had something but in parentheses so I removed them and cleaned them a tiny bit. I'd be happy for people to propose better examples...

 

Also wonder whether some best practice examples of longer descriptions would be helpful? The extension may not be the right place for them, but a separate note might do the trick.

 

Steve also suggested this. For now I put it in a note as out of scope, with a question about whether it would make sense to link to some other document...

 

Thanks for the review. I updated the document: http://dvcs.w3.org/hg/html-proposals/raw-file/default/longdesc1/longdesc.html

 

cheers

 

Chaals

 

-- 

Charles McCathie Nevile - Consultant (web standards) CTO Office, Yandex
chaals@yandex-team.ru Find more at http://yandex.com