Re: [css3-background] last call for comments on "Backgrounds and borders"

On Nov 19, 2009, at 9:24 PM, Tab Atkins Jr. wrote:

>> I don't care strongly about this, but I wish to point out that the
>> discussion as minuted sounds like people thought I was proposing to
>> *require* slashes, which was not my intention.  Rather, I thought it
>> would be friendly to *permit* slashes between any two option groups.
>> As is, authors have to remember that you *do* put a slash between slice
>> and width, width and outset, but *not* between source and slice or
>> before repeat.  Which is fine (especially now that I realize what || in
>> the syntax actually means) but for people who don't want to remember
>> that, allowing a slash would make life simpler.
> 
> Well, the rule is basically "put slashes between groups of numbers".
> We can tell keywords apart from each other; numbers are the only thing
> that needs it.  This is what we do for other properties that use a
> slash - it's only used in the rare places where we have multiple
> numbers that can't be disambiguated purely by position.
> 
> So it's not really necessary to remember precisely where the slashes
> go, just that you put it between groups of numbers.  I think that's
> pretty easy.

Yeah, it seems unlikely that many authors will get the urge to put a slash next to a url() or keyword like "repeat", but they will need ways to separate groups of numbers (or number & unit groups), and that is only where the slash is needed.