Re: Allow other doctypes

On Jun 16, 2007, at 7:41 PM, Ben Boyle wrote:

>
>> Conforming HTML4 and XHTML1 docs will not become non-conforming  
>> HTML4 and
>> XHTML1 docs. They'll remain conforming HTML4 and XHTML1 docs. They  
>> won't
>> be conforming HTML5 docs because they aren't HTML5 docs in the first
>> place. I don't see this as a problem.
>
> Absolutely. Doctype is the only way I (as an author) know of to
> indicate my intentions to a UA.
>
> For example, if I want a document treated as HTML 4.01 Strict I would
> indicate this with:
> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
> "http://www.w3.org/TR/html4/strict.dtd">
>
>
> Likewise XHTML 1.0 Strict:
> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
> "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

These doctypes won't actually have any effect on the processing of  
your document except to trigger standards mode instead of quirks mode  
(which mostly affects CSS processing, not HTML). They will have the  
exact same effect as each other, and would have the same effect as  
HTML 4.01 or XHTML 1.0 frameset or transitional docypes. In  
particular the XHTML doctype will not trigger XML parsing.


> And I can indicate HTML5 using: <!DOCTYPE HTML>
> (This looks to me like it will cause problems beyond HTML5 ... how are
> we going to indicate documents are HTML5 or HTML6 or HTML* if they
> only say "DOCTYPE HTML" ?)
>
> UAs are going to honour this right? They are not going to start
> treating anything with <!DOCTYPE HTML PUBLIC "-//W3C ... (etc) as
> HTML5, are they?

Depends on which UA, Mozilla, Safari and Opera likely will, just as  
today they treat documents with the HTML 3.2 doctype as HTML4.

> I am also curious how HTML5 documents are handled in UAs that don't
> understand HTML5. This is my primary interest in "backwards
> compatibility" because the day I start producing documents using HTML5
> it will be the #1 issue to deal with. Mostly because we'll be waiting
> years until browsers are updated (think of all those organisations
> that mandate a corporate browser for all staff... they resist
> upgrading! ;)

They would be treated as HTML 4.01 in standards mode in existing UAs.

> I intend to do some testing with HTML5 backwards compatibility soon
> (so I guess I'll be flagging documents with "<!DOCTYPE HTML>") on
> sites where there's no risk if things go horribly wrong (no different
> to deciding to use application/xhtml+xml on a private site I think).
> I'd encourage all authors to do this ... start using HTML5 today where
> you can! That'll show us where the issues (for authors) are.

Received on Sunday, 17 June 2007 03:38:40 UTC