Re: ISSUE-4: Versioning, namespace URIs and MIME types ISSUE-60

Hi Ian,

On Feb 20, 2009, at 5:31 AM, Ian Hickson wrote:

> On Thu, 19 Feb 2009, Robert J Burns wrote:
>>>
>>> The only problem I was trying to show is that an implementation that
>>> implements both XHTML2 and XHTML1 in the same namespace would be  
>>> faced
>>> with an irreconcilable difference in semantics when an element in  
>>> the
>>> "http://www.w3.org/1999/xhtml" namespace with the tag name "img" is
>>> created without any other context, since the two specs have  
>>> conflicting
>>> requirements (or rather, since XHTML2 has requirement that  
>>> conflict with
>>> the requirements imposed by legacy content). This is merely  
>>> intended to
>>> show that if XHTML2 does use the same namespace as XHTML1, the two
>>> languages cannot be sanely implemented in the same user agent.
>>
>> Certainly it can be implemented by the same user agent, it just  
>> requires
>> error-handling specified either in a standard fashion or by each
>> individual user agent.
>
> No, as described in my earlier e-mails, the two specifications  
> actually
> have contradictory requirements.

Yes, the two specification have different requirements, but those  
requirements are not contradictory or in conflict. It is only the  
decision to specify incomplete error-handling in this area that makes  
the requirements in conflict at all.

>>> and that any compatibility issue that XHTML2 has is actually not a
>>> clash with XHTML5 but a clash with XHTML1.
>>
>> We still haven't identified any clashes at all (none that cannot be
>> handled by some basic error-handling). The failure of HTML5 to  
>> specify
>> such error handling is a problem as far as I am concerned.
>
> No, HTML5 actually does fully define the error handling here, as  
> described
> in my earlier e-mails. In might not be the error handling you  
> _want_, but
> that's a different matter.

Yes Ian, I understand the error-handling specified in HTML5. However,  
with better error-handling the issue disappears and as a great side  
benefit HTML5 gets better accessibility capabilities in that authors  
can optionally specify multi-paragraph and semantically rich alternate  
text for images. What could possibly be standing in the way of getting  
the error handling that I _want_ (meaning error-handling that  
facilitates better accessibility authoring for HTML5). Is it more  
important to create a false conflict between HTML5 and XHTML2 then it  
is to support better accessibility?

Take care,
Rob

Received on Friday, 20 February 2009 15:59:21 UTC