Re: [html4all] New issue: IMG section of HTML5 draft contradicts WCAG 1 & WCAG 2 (draft)

John Foliot wrote:
> (Slightly trimmed list to reduce overload)
> 
> Julian Reschke wrote:
>> In general, requiring values for things that can't always be provided
>> is a bad idea. It always leads to authors making up values, which
>>   makes the situation *worse* for the people depending on it.
> 
> You know, I've heard this opinion expressed numerous times, but have yet to
> see any evidence at all to substantiate this claim.  Please explain in
> normative and technical terms how this is "worse", else remove the claim
> from the discussion.
> 
> Thank you.

Evidence, as in examples?

- HTTP servers sending a default content type for resources where the 
content was unknown (extremely harmful)

- WebDAV servers returning the name of the system locale for the 
DAV:getcontentlanguage property? Returning the last path segment as 
DAV:displayname?

Believe me, I've seen lots of bad values for things where implementors 
thought that making something up is somehow better than not returning it 
at all. And "img/@alt" certainly is part of that.

BR, Julian