Re: [csswg-drafts] [css-functions-mixins] spreading comma separated var values into multiple arguments by default when calling a custom function (#13927)

While I think the no-spread-by-default behavior would be more accurate to author expectations and use generally, I agree that it's weird to make this change in one place only – when we're compat-constrained in every other context. 

In terms of syntax, this feels like an avoidable bonus footgun on top of the existing footgun – where authors now need to learn two different solutions for managing spread in different contexts (that are otherwise designed to feel similar). One syntax is needed to _stop_ spread from happening in provided functions, and another (new) syntax is needed to _request_ spread in custom functions.

I know there are also parsing advantages to the no-spread option, and I'm open to the group deciding the advantages outweigh the issues here – but I do think this is a pretty surprising lack of consistency between CSS functions and… CSS functions.

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Received on Friday, 15 May 2026 16:34:24 UTC