Re: mixed signals on "Writing HTML documents", tutorial, etc.

(I've taken this to the archive list since Dan seemed to suggest we 
shouldn't rehash this in the public-html list again.)

On Tue, 19 Jun 2007, Philip & Le Khanh wrote:
>
> The question should really have been "How can all valid instances of 
> HTML 5 also be valid instances of HTML 6 and /vice versa/, if HTML 6 
> neither adds to nor removes from HTML 5 ?"

It's not really clear to me that this is an interesting question. I mean, 
once HTML6 is out, who cares what HTML5 says?


> Because this is the question that is at the core of things. A validator 
> is not required to validate one trivial example : it is required to 
> validate /all/ examples with which it is presented, and thus there are 
> two possible scenarios : (1) It can determine unambiguously from the 
> DOCTYPE with which version of HTML the document claims to be conformant, 
> and then it can verify that claim; or (2) it cannot tell from the 
> DOCTYPE with which version of HTML the document claims to be conformant, 
> in which case it has to validate the document against all possible 
> specifications that require nothing more explicit than <!DOCTYPE HTML> 
> and report with which of these, if any, the document conforms.

That's one option, possibly not the most useful. There are two more 
options, one is to simply always validate against the latest version that 
has that DOCTYPE (this is, IMHO, the most useful option), and the third 
option is to provide the user with the option to pick which version to 
validate against (that's e.g., what the CSS validator does).


> > The merits _aren't_ obvious. The drawbacks are many, and serious, but 
> > the benefits seem slim and dubious. (This has been discussed to great 
> > lengths in this mailing list over the past months.)
> 
> The benefits seems so obvious (and so essential), and the drawbacks so 
> minimal, that I am at a complete loss to understand how the proposal to 
> drop versioning can ever have arisen.

What are the benefits?

The drawbacks, the cons, the problems caused by versioning, are:

 * Authors will check their documents against obsolete versions of the 
   spec (as, e.g., authors today check their documents against HTML4 
   instead of HTML4.01), meaning that they do not benefit from the fixes
   that newer versions of the spec have received, and thus that their 
   pages are not optimally conformant and accessible.

 * An implementor may be tempted to implement a new rendering engine per 
   version, leaving their old rendering engines with undocumented bugs, 
   and forcing other implementors to implement a growing number of engines
   just to compete, eventually leading to the inability for other vendors
   to compete, and thus to the stagnation of the Web and its failure in 
   the face of proprietary technologies (as, e.g., is already happening 
   with IE8, and as has been experienced, in part, with "quirks mode").

 * The editors of future versions of the specification will be tempted to
   use versioning as a means to fix compatibility problems, instead of 
   picking the harder, but ultimately better, option of addressing 
   problems in the language itself (as, e.g., people have suggested 
   several times already for HTML5).

 * Authors of Web pages merely copy-and-paste the boilerplate text at the 
   moment, so the shorter and simpler we make it the better; the more we 
   make the boilerplate change from year to year the more difficulty 
   authors will have adapting.

See also:
   http://lists.w3.org/Archives/Public/public-html/2007JanMar/0440.html
   http://lists.w3.org/Archives/Public/public-html/2007JanMar/0433.html
   http://lists.w3.org/Archives/Public/public-html/2007Apr/0279.html

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

Received on Tuesday, 19 June 2007 21:30:40 UTC