Re: [xml-dev] XHTML 5 and validation

[David Carlisle <davidc@nag.co.uk>]

On 18/05/2011 20:06, Jesper Tverskov wrote:
>   For years and implemented all over the place, we
> have been used to get the validation we expect in one step

but what validation do you expect? validating a document served at 
text/html as xhtml (or xml generally) is not (and was never) a good idea 
as it will not be parsed as XML by any relevant user agent, so
using xml to validate it is misleading at best.

html5 changes the rules to make it _possible_ to serve well formed xml 
as html for the first time. using HTML4 and XHTML 1, then a document 
that is syntactically xhtml, if served as html is basically just html 
full of syntax errors that only worked at all because the browsers did 
not parse html as specified, and because they don't report syntax errors.

Personally I'd have pushed to go further (and make more uses of xml 
empty syntax conforming) but already, html5 goes a long way beyond 
html4/xhtml1 in allowing people to serve well formed xml as text/html.

David