(recommended) is the author’s opinion.

• NIP-01 Basic protocol flow description (required)
• NIP-04 Encrypted Direct Message (deprecated but still in use)
• NIP-09 Event Deletion Request (recommended)
• NIP-11 Relay Information Document (recommended)
• NIP-13 Proof of Work
• NIP-17 Private Direct Messages
• NIP-26 Delegated Event Signing (deprecated)
• NIP-29 Relay-based Groups
• NIP-40 Expiration Timestamp
• NIP-42 Authentication of clients to relays
• NIP-43 Relay Access Metadata and Requests
• NIP-45 Event Counts
• NIP-46 Nostr Remote Signing
• NIP-50 Search Capability
• NIP-59 Gift Wrap
• NIP-62 Request to Vanish (recommended)
• NIP-66 Relay Discovery and Liveness Monitoring
• NIP-70 Protected Events (recommended)
• NIP-77 Negentropy Syncing