[html4all] XHTML2 and alt

[Leif Halvard Silli]

Robert J Burns 2008-08-28 22.03:

> On the issue of technical fallback versus media preferential fallback  
> versus textual fallback, I fear I'm not understanding you at all. In  
> terms of instructions for adding plugins/handlers, I'm fine with the  
> UA handling that in a localized fashion (especially since much non- 
> text media is inherently internationalized).

Then read what HTML 5 talks about regarding what kind of fallback 
a user should receive in case it is an old UA which do not 
understand the video element. [For old UAs, there would, I guess, 
be no other way to use the fallback, so one would, in fact, have 
to use the fallback for two purposes.]

But fallback of OBJECT is often used in exactly the same way. 
Which indicates to there is a problem here.

Sure, the UA can explain about lack of video plug-ins and perhaps 
even also provide a direct link to download the video, and may be 
even offer the user to read the fallback. The user would then have 
to indicate that he do not want automatic fallback to the textual 
fallback. But nothing about such behaviour is specified. Which is 
why I try to discuss this.

> On the issue of syntactic errors, I don't think leaving alt off of an  
> attribute is a syntax error. It is invalid, but neither a syntax error  
> nor a well-formedness error.  Basically, I agree with what Al Gilman  

> says[1]. A syntax error would be to add an atl attribute (intending to  
> add the alt attribute).


> [1]: <http://lists.w3.org/Archives/Public/public-html/2008Aug/0871.html>

@alt is required in HTML 4. Many would, like Henri Sivonnen, link 
lack of a required attributes to syntax, especially when the 
attribute is both required *and* can be empty. But I can see that 
this might formally be incorrect.

Also Al links it to syntax, as the first thing he says is that 
lack of @alt would be non-conforming to <quote>The syntax, as well 
as the accessibility guidelines.</quote>

What he further says is that there is no syntactic link between 
"important but an alternative is unavailable" and the lack of 
@alt. If precense of a third attribute or e.g. use of <figure> 
would permit @alt to be dropped, then I guess he would say there 
were a syntactic link.

Hence I think he uses syntax as I have done.
-- 
leif halvard silli