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Compatibility with XHTML2

From: Smylers <Smylers@stripey.com>
Date: Sun, 15 Jul 2007 23:20:10 +0100
To: HTML WG <public-html@w3.org>
Message-ID: <20070715222010.GQ5621@stripey.com>

Robert Burns writes:

> On Jul 15, 2007, at 4:09 PM, Smylers wrote:
> 
> > Robert Burns writes:
> > 
> > > On the UA side, we can direct UAs how to handle this situation.
> > > For example, "UAs that recognize <img> as having content (as in an
> > > XML processing UA) must treat the contents of an <img> element as
> > > fallback in the same fashion as the <object> element." However, we
> > > guide authors conformance on this, I think that would be the
> > > prudent way to go for UA conformance. For forward compatibility,
> > > this UA conformance seems imperative.
> > 
> > Why?  Compatibility with what?
> 
> Our design principles also place an importance on forward
> compatibility.

I've just looked at:

  http://www.w3.org/html/wg/html5/principles/#compatibility

It mentions "forwards compatibility" only to label it as an unclear
term, then it defines five specific sorts of compatibility we do care
about.  None of those seem particularly concerned with being compatible
with other, not-yet-widely-adopted specifications.

> http://www.w3.org/TR/xhtml2/mod-image.html#s_imagemodule

Is XHTML2 implemented anywhere?  Does anybody use it?  Our design
principles make no direct mention of XHTML2 -- though they do include
'Evolution Not Revolution', which could be interpreted as a reaction
_against_ XHTML2's approach of being revolutionary.

I thought it was widely recognized that XHTML's approach had not found
popular approval, so HTML5 is a second attempt at solving the similar
problems (in a different way).

Insisting that HTML5 be compatible with XHTML2's syntax -- that is,
recognizing and correctly interpreting XHTML2 document fragments --
would effectively involve HTML5 absorbing XHTML2 wholesale.  Which
surely mostly defeats the purpose of having a separate HTML5 working
group in the first place.

However, HTML5 does note:

  XHTML2 and this specification use different namespaces and therefore
  can both be implemented in the same XML processor.

So at least from the point of view of using XHTML5 and XHTML2 together
they are compatible.

Smylers
Received on Sunday, 15 July 2007 22:20:23 GMT

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