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Re: ISSUE-30 (Longdesc) Change Proposal

From: Maciej Stachowiak <mjs@apple.com>
Date: Tue, 08 Dec 2009 11:39:11 -0800
Cc: "public-html@w3.org" <public-html@w3.org>
Message-id: <88D18920-8587-434A-B90E-F7A0000AB36F@apple.com>
To: Charles McCathieNevile <chaals@opera.com>

Thanks for providing a Change Proposal for this issue! The chairs are  
reviewing Change Proposals to ensure that they meet the required  
structure. Here is our feedback on this Change Proposal:

(1) This Change Proposal lacks a clearly marked Summary section  
(perhaps some of the introductory text is a summary, but that is not  
clear).
(2) This Change Proposal lacks a clearly marked Details section, and  
does not provide sufficient detail to identify a specific change. It's  
mentioned that many sections may change, but does not identify  
explicitly which changes are required by the Change Proposal.
(3) This Change Proposal lacks an Impact section.

We suggest updating the Change Proposal to reflect the feedback in  
points (1), (2) and (3).

Regards,
Maciej

On Oct 26, 2009, at 10:53 AM, Charles McCathieNevile wrote:

> Hello,
>
> I would like to propose that the longdesc attribute from HTML 4 be  
> retained in HTML 5 as an allowed attribute on images. This implies  
> the following changes to the spec:
>
> at http://dev.w3.org/html5/spec/text-level-semantics.html#the-img-element 
>  img would also become interactive content with longdesc present.  
> The longdesc attribute would be listed as an attribute for the  
> element.
>
> The attribute is described already in HTML 4 [1] and the description  
> can be re-used, although it should be made clear that the URI to  
> which longdesc refers can be a relative reference to some part of  
> the same page (in order to be explicit about which content is  
> associated with the image), or a different page. The example, which  
> references an image but appears to provide useless alt text should  
> not be copied from HTML 4.
>
> Other sections that may change:
> 4.8.2.1.1, 4.8.2.1.2, 4.8.2.1.3 should all mention that a longdesc  
> *may* be provided to provide a detailed *description* of the image,  
> e.g. to help a person who cannot see it to find it from a description.
>
> 4.8.2.1.5 should mention it as a way to make the association between  
> an image and the relevant text explicit.
>
> 4.8.2.1.6 should mention it as the preferred way to point to a  
> description of the image if this is desired, rather than mis-using  
> the alt attribute for this purpose.
>
> 4.8.2.1.9 should mention that where an image is a key part of the  
> content, it should have sufficient text in the alt attribute to  
> replace the image, and using the longdesc attribute for critical  
> information is a mistake. However, it can be used for additional  
> information if desired.
>
> RATIONALE:
> This has been a controversial topic. It is clear that longdesc is  
> relevant only to a fraction of images on the Web, and that it is  
> only provided in a few of the cases where it is actually relevant.  
> It is also clearly subject to bogus values to a large extent  
> (perhaps the majority of the time). And its use is relatively  
> limited, even by those who might be expected to appreciate it.
>
> However, it has been implemented multiple times successfully. The  
> fact that there is bad data associated might account for low overall  
> usage, but has relatively little impact on implementations, which  
> can readily choose to simply ignore values which are not URIs, or  
> even to present the value to the user, and relatively little impact  
> on the user, who can still benefit from a *good* usage.
>
> This would require conformance checking to accept the attribute as  
> valid, and would imply maintaining the existing requirement on  
> Authoring Tools[2] to allow the author to use this functionality. It  
> would maintain conformance of HTML-4 tools and content, rather than  
> the current expected change leaving them non-conforming.
>
> [1] http://www.w3.org/TR/REC-html40/struct/objects.html#adef-longdesc-IMG
> [2] http://www.w3.org/TR/ATAG-10/ makes several relevant requiremnts
>
> cheers
>
> Chaals
>
> -- 
> Charles McCathieNevile  Opera Software, Standards Group
>    je parle franšais -- hablo espa˝ol -- jeg lŠrer norsk
> http://my.opera.com/chaals       Try Opera: http://www.opera.com
>
Received on Tuesday, 8 December 2009 19:39:51 UTC

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