[whatwg] Alt text authoring Re: Conformance for Mail clients

[Maciej Stachowiak]

On Apr 21, 2007, at 11:30 AM, Jon Barnett wrote:

> I've been following this and gathering thoughts.

[...]

> 2. Images that are content but don't represent text (though they  
> may be accompanied by a caption - even if the caption could be the  
> alt text, it would be redundant with the caption repeated in the  
> markup)
> <p>These are my vacation photos:
> <ul><li><img src="grandcanyon.jpg">My wife and I at the Grand  
> Canyon...</ul>

[...]

> For (2), authors have a few choices:
> (a) Use the <img> tag and leave the alternate text blank. [...]  
> Requiring the alt attribute causes a problem here and simply  
> leaving the attribute's value blank doesn't clear up enough ambiguity.

[...]

> (c) Use the <object> tag with fallback content.  This is probably  
> the most useful option doesn't naturally cause any problems.  The  
> only real issue is that neither HTML4 nor HTML5 explicitly describe  
> (1) and (2), and say to use <img> for (1) and object for (2)

How is an <object> with empty fallback content different from an  
<img> with an empty alt value? It seems like it is just as ambiguous,  
since if the fallback content were non-empty it should be substituted.

I think a better option would be to distinguish alt="", and use that  
for images in the content that add no meaning as the draft says  
today, and no alt attribute at all for images that are meaningful,  
but where a text description is not available or appropriate. We  
could limit <img> with no alt attribute to content generated by  
WYSIWYG editors, in the same way as <font>. Or something like that.  
Basically we can distinguish the two cases by alt="" and entirely  
omitted alt.

Regards,
Maciej