https://guides.getalby.com/overall-guide/alby-lightning-account/nostr-x-alby/connect-your-alby-wallet-using-nwc-to-nostr-client-nostur

Stands for Nostr Wallet Connect and unlocks One Tap Zaps with multiple Clients.

As far as I know this is only available for some custodial wallets.

Please let me know if this is wrong.