No not there could be a new kind I suppose that's a list of pubkeys and acts as a whitelist or blacklist.
Huh? I meant a way for a relay to only accept certain event kinds.
nostr:nprofile1qqsyvrp9u6p0mfur9dfdru3d853tx9mdjuhkphxuxgfwmryja7zsvhqppemhxue69uhkummn9ekx7mp0qythwumn8ghj7anfw3hhytnwdaehgu339e3k7mf0qyghwumn8ghj7mn0wd68ytnhd9hx2tch2deau was working on some sort of limits nip that has a lot of info a relay could use to set it's policies.