Re: Need differentiator between "no alt text provided" and "no alt text necessary"

On Mon, 2 Feb 2009, Maciej Stachowiak wrote:
> On Feb 2, 2009, at 3:32 PM, Ian Hickson wrote:
> > On Mon, 2 Feb 2009, James Craig wrote:
> > > > > 
> > > > > If the src attribute is set and the alt attribute is not The 
> > > > > image is assumed to be a key part of the content, and there is 
> > > > > no textual equivalent of the image available.
> > > > 
> > > > "is assumed" is descriptive phraseology. Whom is it assumed by? 
> > > > Why?
> > > 
> > > Assumed by:
> > > 
> > > 1. User agents, in order to give an appropriate experience to users. 
> > > 2. Search engines, in order to index appropriate content.
> > 
> > But what is it in the spec that makes them assume this? It can't be 
> > the sentence that describes that assumption, since that's a 
> > descriptive sentence. Hence my wording -- it's the sentence that 
> > defines that the assumption is ok.
> > 
> > (Another way of phrasing it could have been "should be assumed", but 
> > that defines implementation behavior and in this case it was the 
> > semantic that I was trying to define.)
> 
> Perhaps one way to make this clear would be to leave the sentence as is, 
> and separately say that user agents either MAY or SHOULD assume that 
> such images are a key part of the content lacking a textual equivalent. 
> That would leave the definition of the meaning intact and clarify what 
> is expected of user agents, while avoiding the ambiguous passive voice 
> construction.

The very next sentence is:

   If the image is available, the element represents the image specified 
   by the src attribute.

...and the Rendering section (which I'm writing as we speak) will say 
something along the lines of "user agents are expected to render <img> 
elements as replaced elements showing the image they represent" or some 
such like.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

Received on Monday, 2 February 2009 23:40:29 UTC