[whatwg] a few comments to Webforms 2.0 Call For Comments

Matthew Thomas mpt at myrealbox.com
Sat Jul 31 20:10:46 PDT 2004

On 31 Jul, 2004, at 11:58 PM, Henri Sivonen wrote:
> ...
> First of all, the solution needs to apply to XHTML as well as HTML. If 
> we still assume XML is to be taken seriously (and not as tag soup), 
> doctype sniffing on the XML side is totally, utterly bogus.

That's a presumptive definition of "seriously". In the long run, it 
*may* be the case that treating XHTML as tag soup is the only "serious" 
way of doing it. (I know that's a heated debate that doesn't belong on 
this list, but it's probably heated because the answer's not yet 
obvious enough for "seriously" to mean anything.)

> The reason why it is bogus is that including a DTD by reference and 
> pasting it inline are supposed to be equivalent for validating XML 
> processor and in the latter case you don't see a public identifier for 
> the DTD. Hence, using the public identifier for any purpose other than 
> locating the DTD is just plain wrong. Of course, sane real-world XHTML 
> user agents use non-validating XML processors which makes the 
> inclusion of the doctype declaration rather pointless.

So do any real-world XHTML UAs handle a DTD pasted inline, or is this 
just a theoretical argument?

> ...
> Now, similar argumentation does not work on the HTML side if we agree 
> not to pretend that real SGML is being processed. Doctype sniffing is 
> a tag soup solution to a tag soup problem.

That's an extrapolation from a single data point. The only use of 
doctype sniffing *so far* has been to handle quirky style/layout 
expectations of old pages (and in the case of table style inheritance, 
they wouldn't even need to be tag-soup pages). In the long run, doctype 
sniffing may become a general-purpose method of changing *any* 
undesired behavior (whether de-facto or de-jure) of old syntax in new 
spec versions.

> Still, doctype sniffing is already confusing and convoluted enough for 
> casual authors. (See http://iki.fi/hsivonen/doctype.html for subtle 
> differences between user agents.)  I think perturbing it further is a 
> bad idea.

Sure, but it may be unavoidable, just like it is with natural 
languages. (Try running "The Canterbury Tales" through a Modern English 
spellchecker or grammar checker, for example.)

> Besides, you can't force the existing installed base of browsers to do 
> new tricks with doctypes which would mean different defaulting.
> ...

Which is probably why Matthew Raymond's proposal doesn't require the 
existing installed base of browsers to change anything.

Matthew Thomas

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