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Re: More about <alt>

From: Sander Tekelenburg <st@isoc.nl>
Date: Thu, 6 Sep 2007 14:59:19 +0200
Message-Id: <p06240696c305a58b0bfe@[192.168.0.101]>
To: public-html@w3.org

At 14:03 +0200 UTC, on 2007-09-06, Olivier GENDRIN wrote:

> On 9/6/07, Sander Tekelenburg <st@isoc.nl> wrote:

[...]

>> <img id="mergedcells" src="mergedcells.gif">
>> <!-- anything or nothing -->
>> <alt for="mergedcells" title="short textual equivalent"
>> type="text/html">blah</alt>
>> <alt for="mergedcells" title="long description" type="text/html>blah,
>> blah</alt>
>> <alt for="mergedcells" title="tabular equivalent" type="text/html">
>> <table border="1" summary="This table gives some statistics about fruit
>> flies: average height and weight, and percentage with red eyes (for both
>> males and females).">
>> <caption><em>A test table with merged cells</em></caption>
>> <tr><th rowspan="2"><th colspan="2">Average
>>     <th rowspan="2">Red<br>eyes
>>     <tr><th>height<th>weight
>>     <tr><th>Males<td>1.9<td>0.003<td>40%
>>     <tr><th>Females<td>1.7<td>0.002<td>43%
>> </table>
>> </alt>
>
> Ok, I understand better what you meant. But in that case, I wish that
> your 3 titles where replaced by an attribute that would said :
> 'alternative', 'short description', 'long description' (@role ?).

I don't think @title needs to be removed, even if predefined values would be
added thropugh @role. @title might then be less necessary, but might still be
useful, right?

As to predefined values itself: I can see that such a thing might be useful.
I'm trying to hold it off though, because I suspect that there is no limit to
the sort of equivalents authors might want to provide. It doesn't seem
realistic to me that we can think ahead of descriptive terms that will cover
all situations. So even we we define some generic predefined values like
"short", "long", "audio", "captioned video", etc. we would still have to
allow authors to use some non-predefined value: "table", "slide", "pdf",
".doc", "x", "y", "z".

Note that in the <alt> proposal, @type is required already, and UAs are
required to make that available to users, preferably translated into a
user-friendly form.

I haven't yet given much thought to the specifics if MIME types in this
context though. Possibly not all MIME types will be indicative enough. Any
thoughts on that, anyone?

Clearly audio/ogg, audio/mpg, audio/mp3, etc. would allow the UA to indicate
that the equivalent is aural. But does the same apply to vague container
formats such as .avi and .mov?

What can probably not be indicated through @type is something like a
captioned video. Can we think of more such cases? (The more there are, the
more important it gets that authors provide useful @titles, which they might
get wrong, which would increase the need for something like @role.)


-- 
Sander Tekelenburg
The Web Repair Initiative: <http://webrepair.org/>
Received on Thursday, 6 September 2007 13:05:59 GMT

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