Re: Doctypes and the dialects of HTML 5

Lachlan Hunt wrote:

>> But browser is not only component which deals with HTML markup. Let's
>> say you for some reason want to use only subset of HTML which is known
>> to be supported on all mobile devices. You should be able to indicate
>> which version of HTML you are using for tools which are used to
>> generate markup (e.g. HTML editor) or check markup (validator which
>> checks that you are using only elements that are defined in particular
>> version of HTML).
> Why does such an indication need to be included in the document itself?
>  Such use cases better addressed through options provided by the tool.

This can work if you use single tool. But imagine document workflow,
where page is consecutively edited and revised by different people using
different tools. But they for some reason decided to use only
well-defined subset of "full HTML". HTML should offer standardized
mechanism for specifying this my subset of HTML x.y.z. Tools that cares
can use this information, other tools (including common browsers) will
ignore such information.

>  Although, in my experience, human knowledge of browser limitations is
> far superior to the information provided by any existing tool.

This could be true if you as human count only few geeks that spend days
hacking around browser bugs. But most of the content served on Web is
created by people who do know nothing about HTML, they are just using tools.

> To illustrate my point, consider the XHTML mobile profile.  In practice,
> it's a joke.

Indeed. Hardware of mobile phones is improving faster then any XHTML-MP
language specification could be written ;-)

> Besides, the whole concept of a mobile profile is backwards. 

Only to some extent. I agree that it is silly to have two different
languages with different element sets. OTOH, mobiles will always have
smaller screens and limited input facility, so from point of usability
view you should sent more brief output to mobiles. One large page
suitable for my 19" LCD would be much readable as several smaller pages
served to mobile agent.

>> Of course you can specify version you want to use in your
>> editor/validator/... externally, but this very impractical and it
>> doesn't work.
> It's not impractical, it's way validation should work.  The interesting
> question is not whether a document conforms to the rules it expresses
> for itself, but whether it conforms to the rules specified by the one
> asking the question.

But in order to do this you need to infer which language you are using.
Sometimes it is enought to know that you are using HTML/XHTML, sometimes
you are interested in particular version of HTML/XHTML.

And specifying version is not the same as saying to which rules document
should conform. I'm not proposing that document should contain link to
some sort of schema (be it DTD, WXS, RELAX NG, or whatever). I'm just
saying that in order to pick right schema, it is sometimes necessary to
know more then just MIME type (for HTML) or namespace (for XHTML).

> When HTML6 comes out in the future, hopefully it will be designed in a
> that ensures that conforming HTML5 documents remain conforming HTML6
> documents.  i.e. HTML5 will just be a subset of HTML6.

Hopefully. But having version leaves doors open to either way of future

> In the event that they are slightly incompatible, conformance checkers
> should allow authors to choose HTML5.  They should generally default to
> the most recent edition of HTML.


>> But it was deprecated because at the time of HTML 4 development the
>> intent was that !DOCTYPE will carry version information:
>> Nowadays it is known that !DOCTYPE is really not very useful for this
>> purpose.
> Exactly!  And now that we know versioning using DOCTYPEs isn't useful,
> why should we re-introduce it using any other method?

The problem is not in versioning itself, but in !DOCTYPEs.

>> However rules for composing version identifier should be defined.
>> E.g. something like DocBook uses:
> I don't care about the mistakes made by DocBook.

Mistakes? Could you explain this more, or are you just shooting?

  Jirka Kosek      e-mail:
       Professional XML consulting and training services
  DocBook customization, custom XSLT/XSL-FO document processing
 OASIS DocBook TC member, W3C Invited Expert, ISO/JTC1/SC34 member
 Want to speak at XML Prague 2007 =>

Received on Sunday, 25 March 2007 09:22:31 UTC