Re: Conditional CSS sections based on property support

> @group 
> {
...
>   background-color: #0F0;
....
>   some-unsupported-property: blah !required;
>   color: #F00;
>  }
> } /* end of group */
> 
> The first style would ordinarily be fine, the second style is required
> for the application of the entire group. The second style will fail if

This is at best a flawed example.  In this context, color and background-color
almost certainly must be !required, as colours should always be set in 
sets to ensure contrast.