mezzoblue § IE7 Conditional Comments relates back a Question & Answer session with Chris Wilson and Brian Goldfarb of Microsoft, about IE7 and conditional comments. Transcribed by Molly Holzschlag (she has also posted about the rest of the meeting: » WaSP Microsoft Task Force Update: Upcoming Products, XAML, Acid2, SXSW, and IE7 Revealed).

One particular quote really has me stumped.

Why not implement conditional comments in CSS syntax, so we can move our filtering into external files and keep our markup clean?

Chris replies:

"I think it would be great if we provided a mechanism like conditional comments inside CSS. We’ve [Microsoft] thought about it, we’re not going to do it in IE7 because we want to do it in a sane, rational way. You’ll want conditional comments to be backward and forward compatible. Tough to design that into CSS so that it will actually work."

Microsoft wants us to do this to all our documents, to allow for IE6:

<!--[if IE]> to IE-specific CSS file...

As I've said already, I think it would have been much better to provide conditional comments in the CSS rather than the page source. All they had to add to IE7 was the ability to parse something like this in a CSS file:

/* [if IE 7] 
[endif] */

...which both validates and works in other browsers (as in, it's ignored). So why on earth was it not a "sane and rational" approach?