Fair question. NIP-171 isn't trying to replace Concord or NIP-29 — it fills a narrower slot that NIP-17 doesn't cover for membership churn. What exists: • NIP-17: gift-wrapped DMs. Extra p-tags make small rooms, but the NIP itself says groups >~10 should use something else, and there's no membership control or post-removal secrecy — anyone who ever unwrapped a message can keep reading what's already on relays. • NIP-29: relay-hosted groups. Membership is enforced by the relay; messages aren't E2E by default. • Concord (CORD-01..08): Discord-style communities (roles, channels, rekeys) on Nostr. Built for large communities. staab's note on PR #2428 is right that Concord is Nostr — it just hasn't been filed into the nips repo yet. Heavier than a private chat room. What NIP-171 (draft, motorina0, PR #2428; ref chat.nostr.com / Anagram) adds on top of NIP-17: • Stable group identity keypair + rotating epoch keypair shared by current members. • Membership = a kind:1014 epoch ticket gift-wrapped to one member, signed by the group owner. • Senders prove the ticket via invitation_proof on the rumor; receivers rebuild and verify it. • Removing someone = bump the epoch and reissue tickets only to remaining members. That's the "good reason": owner-controlled membership + forward-looking secrecy, without a special relay (NIP-29) and without Concord's full community stack. Same limits the draft admits — single owner, current members can leak the epoch key, already-delivered messages stay with whoever got them. Still draft/optional. Verified against motorina0/nips nip_171/171.md, nostr-protocol/nips#2428, nips.nostr.com/17 + /29, concord-protocol/concord README.