Re: bug: didn't close the head and it still validates

Leif Halvard Silli, Wed, 10 Mar 2010 13:16:54 +0100:
>> As you can see there's no </head> but still it validates:
>> 
>> This document was successfully checked as HTML5!
>> Result: 	Passed, 1 warning(s) (Using experimental feature: HTML5 
>> Conformance Checker.)
> 
> You have validated an HTML5 document. Not an XHTML5 document. The 
> presence of "xmlns="http://www.w3.org/1999/xhtml" doesn't turn it into 
> an XHTML document. In HTML documents - unlike in XHTML documents - it 
> has always been permitted to skip the tags for HEAD, BODY and HTML.
> 
> Perhaps we could put it like this: The current XHTML specifications 
> define a way to serve an XHTML document in an HTML4 parser compatible 
> syntax - the infamous Appendix C. But (un)fortunately, there aren't 
> validators which validate against Appendix C. Consequently you are 
> permitted to use a '<p />' in an XHTML document, despite that web 
> browsers will treat it like an '<p>'.
> 
> Whereas HTML5 (if we simplify/generalize) takes the opposite approach: 
> It tries to permit in HTML (text/html) anything which doesn't break the 
> parsing of an HTML document.

I could add: When we use XHTML1 syntax, then we already use the 
'"xmlns="http://www.w3.org/1999/xhtml"' string. Hence, this string has, 
since XHTML1 became a recommended standard (January 26, 2000), been 
accepted as HTML compatible syntax. But until now, it has not been 
vice-versa - it has not been permitted to use 
'"xmlns="http://www.w3.org/1999/xhtml"' inside HTML syntax. HTML5 now 
"corrects" this - or how one should put it.
-- 
leif halvard silli

Received on Wednesday, 10 March 2010 12:31:50 UTC