[css-fonts] which generic in a font-family list influences system fallback?

[heycam]

Breaking this out from #4442:

@heycam:

Do we need to add wording about which generic, if multiple are listed, influence any implementation specific system fallback?

@jfkthame:

Presumably the first generic mentioned should be the one to influence fallback after we fall off the end of the font-family list.

Is this something we need to have a SHOULD-level statement for in the spec?

[svgeesus]

Yes, we need to add that wording. I agree that the first generic mentioned (regardless of whether it matched to a real font or not) is the best option, because the font stack is a priority ordered list so the first generic should most closely correspond to authorial intent.

[litherum]

the first generic method should be the one to influence fallback

I disagreed in #4442 (comment)