…
…we need those weight values for pronouns.
examples:
Accept-Pronouns: she/her
Accept-Pronouns: they/them, she/her
Accept-Pronouns: he/him, it/it;q=0.8, they/them;q=0.5
Accept-Pronouns: they/them, */*;q=0.7
…hmmmmm…now we need a way to express /you can use these pronouns /if/ you know what you're doing/
(I've seen a couple creatures with pronoun lists like that. My list is this way, too, actually; that's just not currently reflected in my profile)
Maybe a syntax reminiscent of Lisp (and by that I just mean: parentheses)
or how about…
Accept-Pronouns: she/her
Accept-Pronouns: preference=1.0 (they/them, she/her)
Accept-Pronouns: they/them, (preference=0.7 */*)
Accept-Pronouns: (he/him, preference=0.8 they/them), (condition="when beastly", (it/it, preference=0.9 he/him, preference=0.8 they/them))
@moonbolt *blinks* O-okay, I need this now. 
@moonbolt I really need to put this in my bio. Wish it didn't have the ridiculous space restrictions. :3
@IceWolf aww, your instance doesn't let you do more than 4 metadata fields?
@moonbolt Yyyep. ;w;
Tiny display name character limit, too. I don't think I can put an emojo after my name!
@moonbolt [Tested, yep. A regular emoji would work, as it's one character, but even a short custom emoji code is too long to fit.]
@moonbolt Although I was going to put it in the bio itself, since I don't want the "Accept-Pronouns" text cut off. :3
@IceWolf eh, creatures can tell what it's supposed to say even if it does render like that
@moonbolt *nods* I think I'm just a stickler for Proper Rendering. :P
@IceWolf yeah, the way it renders on my client bugs me a little…
…not enough to drop it, though :3
Absolutely horrendous pun
@moonbolt Yes-expressions. 
@moonbolt So maybe something like
((he/him 1) (they/them 0.8) ("when beastly" (it/its 1) (he/him 0.99)))
?
@moonbolt Although I'm not sure that really covers "if you know what you're doing", but I suppose that'd just be another condition.
@IceWolf …hmm…a problem with these syntaxes
it's ambiguous whether other pronouns are included in the conditional list
@moonbolt It is? Oh, I figured that was covered by the parentheses. But that /is/ hard to read.
@IceWolf oh…maybe
I dunno. What else could we do?
@IceWolf …I just saw somecreature who used the vertical bar and tall anglebracket symbols (like quantum physics uses) in their pronoun list
@moonbolt Vertical bar and tall anglebracket? What did that look like? *tilts head, intrigued*
@moonbolt Huh, neat! What does it mean... how would that look with pronouns in it?
@moonbolt Not really based on anything in particular, but easier to read than the Lisp thing maybe?
[he/him 1, they/them 0.8, ["when beastly": it/it 1, he/him 0.95]]
numeric weights make the relative preference explicit, so you don't have to wonder whether they meant /either is totally fine/ or /I prefer the first, but the second is okay too/
…which means that second example should actually be `Accept-Pronouns: they/them;q=1, she/her;q=1` (otherwise it's just as ambiguous as not using this protocol, for creatures who are interpreting it intuitively)