----- Original Message -----
From: "Boris Zbarsky" <[EMAIL PROTECTED]>
To: "Andrew Fedoniouk" <[EMAIL PROTECTED]>
Sent: Thursday, November 30, 2006 9:03 PM
Subject: Re: [whatwg] HTML syntax: shortcuts for 'id' and 'class' attributes
[off list, since it's totally the wrong list]
Oops, didn't realize that, terribly sorry.
Andrew Fedoniouk wrote:
1) HTML5 is backward compatible with HTML4 so any HTML5 aware UA can read
HTML4 files
without any additional setup. That implies HTML4 is a subset of HTML5.
HTML4 is not a subset of HTML5. But HTML4 that's actually used on the web
is a subset of HTML5, generally speaking. Thus any HTML5 aware UA can
render the HTML4 that's used on the web.
2) Any HTML4 aware UA can render HTML5. That is possible only if HTML5
is exactly HTML4 or its subset (but not superset).
HTML5 is not a subset of HTML4. But it's designed in such a way that it
takes advantage of the extensibility features of HTML4. Thus an HTML4 UA
can render an HTML5 page reasonably, though possibly not as well as an
HTML5 UA.
The change you suggest would mean that HTML5 and HTML4 UAs would need
totally different behavior, which is not desirable.
-Boris
So if HTML5 will allow following:
<p.myclass> ... </p>
together with its full and equivalent form
<p class="myclass"> ... </p>
then this will be backward compatible solution as
HTML5UA will understand both forms - classic and simplified.
Am I right?
Andrew.
