This NIP is not yet in main. Here is an overview of PRs referencing this NIP. 
Accessibility (A11y) OPEN @fernandolguevara
NIP-111: Nostr-specific Private Keys from Deterministic Wallet Signatures (Sign-in-With-X) OPEN @0xc0de4c0ffee
NIP-11 extension for Relay Limitations CLOSED @doc-hex