Re: @version rule

On Fri, 27 Jul 2001, Jeffrey Yasskin wrote:
>
> [ @version ]

Here are reasons why this won't work:

  1. Existing UAs don't support it.

     The following:

        @version 1 {
           p { color: blue; }
        }

     ...would never cause a paragraph to be blue, since existing UAs would
     drop the entire rule (it's not valid in the version of CSS they
     support) and future UAs wouldn't mark themselves as CSS1-only UAs.


  2. UAs don't implement a whole level at a time.

     Point me to a *single* CSS1 UA. There aren't ANY. There are lots of
     UAs that implement parts of CSS1, CSS2 and even CSS3, but none that
     implement a single layer. Which level should IE6 claim to support?


  3. You can already do it if you are creative.

     For example, using @media rules:

        /* CSS1 rules here */

        @media all {
           /* CSS2 rules here */
        }

        @media all and (some: media-query) {
           /* CSS3 rules here */
        }

     ...or @import rules:

        @charset "ISO-8859-1";
        @import "css2";
        @import "css3" all and (some: media-query);
        /* css1 */

All three of these issues are, alone, important enough to prevent this
from being added to the spec. Together, however, they show that the idea
is unworkable and not needed. This is in addition to the existing forward-
compatability guidelines and the fact that, as you (I think) pointed out,
the working group is trying to make sure that extensions remain backwards
compatible as well.

HTH,
-- 
Ian Hickson                                            )\     _. - ._.)   fL
Invited Expert, CSS Working Group                     /. `- '  (  `--'
The views expressed in this message are strictly      `- , ) -  > ) \
personal and not those of Netscape or Mozilla. ________ (.' \) (.' -' ______

Received on Saturday, 28 July 2001 02:11:20 UTC