We are using kind 30,000 mostly because I think it is a good idea to create a feed of the muted folks. Since Amethyst shows all kind 30,000 as feeds, it's an easy trick to show the "blocked" feed as well.
But we can go either way.
Nos is using kind 10,000. That’s what’s listed for the mute list on https://github.com/nostr-protocol/nips and in the example of a mute list in NIP-51. Does Amethyst use 30,000?
Discussion
I don't care much either way either. Although showing a feed of the content you already decided you don't want to see seems like a weird feature to me. I think nostr:npub1jlrs53pkdfjnts29kveljul2sm0actt6n8dxrrzqcersttvcuv3qdjynqn is using 10,000 in Coracle and nostr:npub1g53mukxnjkcmr94fhryzkqutdz2ukq4ks0gvy5af25rgmwsl4ngq43drvk is using it in Iris because I was testing Nos's mute functionality with those the the other day. But Damus doesn't appear to be nostr:npub1xtscya34g58tk0z605fvr788k263gsu6cy9x0mhnm87echrgufzsevkk5s.