Re: [CSS21] Are vendor-specific extensions invalid?

Benjamin Hawkes-Lewis wrote:
> Christof Hoeke wrote:
>> I guess a WARNING instead of an ERROR for these cases would be better, 
>> would it not? 
> 
> Only if the definition of CSS 2.1 stylesheet validity is changed. A 
> validator should emit errors when a document is not valid.

probably right, but...

> 
>> A  sheet would still not be "valid" - just "wellformed" though.
> 
> It might be useful to have a tool that could check documents can be 
> parsed according to the CSS 2.1 specification. That would be a different 
> tool to a validator which checks documents are valid according to the 
> CSS 2.1 specification.

... problem is that validating real-world stylesheets might contain 
properties which are available in most browsers (and are useful too) but 
which are not (yet) defined in CSS 2.1. I am not quite sure if that 
example still holds but display: inline-block is AFAIK not in CSS 2.1 
but very useful (I am not even talking about vendor specific props like 
moz-opacioty etc).

IMHO a strict CSS 2.1 validator does help almost no one but the CSS 2.1 
maintainers ;)

If I want to say to a customer "I use valid CSS 2.1" I am severely 
limited, most of the times I have to use invalid CSS 2.1. But the CSS 
would still be "wellformed" but I cannot prove it...

I guess a similar discussion takes place with HTML/XHTML. It just is not 
as difficult (anymore) as there are only very few elements not valid 
(but wellformed) like e.g. <embed> (which still may be replaced with 
valid constructs).

I won't say the validator is not useful but it would be a greater help 
if it also could just check if my CSS is wellformed (or is this actually 
possible?).

Christof