[css-color-5] Custom color profiles: <custom-ident> or <dashed-ident>?

[fantasai]

In general in CSS we use <custom-ident> for CSS-internal identifiers, see @namespace, @font-face, @counter-style. Color 5 proposes to use <dashed-ident> for color profile names (@color-profile), which is inconsistent. Should it be switched to <custom-ident> or is there some compelling reason why color profile names need to be different?

[svgeesus]

Because @tab made me do it :) when he said:

so I guess I lean slightly toward --idents, since the names are declared by the author in the @color-profile rule.
#4654 (comment)

and then added something for me to link to:

Done, you can refer to <<dashed-ident>> now:
#4654 (comment)

[svgeesus]

But in general look at [css-color-4] The color() function <ident> doesn't seem to be future proof #4654 which is where we went for explicitly author defined idents since they can be mixed in with standardized and later-standardized ones:

If not handled carefully, this can result in difficulties adding new CSS-defined values; UAs have to study existing usage and gamble that there are sufficiently few author-defined identifiers in use matching the new CSS-defined one, so giving the new value a special CSS-defined meaning won’t break existing pages.

[tabatkins]

Right, we have dashed-idents specifically for the case where we're mixing them with CSS-defined idents (or would otherwise have parsing ambiguities for some other reason). This is 100% one of those cases, so dashed-ident is required.