Guillaume

About [comma-containing productions](https://drafts.csswg.org/css-values-5/#comma-containing-productions): > If it does not start with a "{" token, then it cannot contain commas or {} blocks `@media unknown(foo, bar) {}` and `@media unknown({}) {}` are...

[cssom-1] Serialization of feature values

4

[*Serializing Media Feature Values*](https://drafts.csswg.org/cssom-1/#serializing-media-feature-values) is poorly defined. This is not really important but hey, it could simply be replaced with [serializing a CSS component value](https://drafts.csswg.org/cssom-1/#serialize-a-css-component-value): keywords in lowercase, base 10...

[css-values-5] Trailing comma in `attr()`

4

Is a trailing comma allowed in [`attr()`](https://drafts.csswg.org/css-values-5/#attr-notation) like in [`var()`](https://drafts.csswg.org/css-variables-2/#using-variables)? > `attr() = attr( ? , ?)` > `var() = var( , ? )` > > In an exception to...