NIP-26
Delegated event signing
NIP-26 describes how one key can delegate limited signing rights to another key. This can support special workflows, but it is not widely recommended for everyday use.
NIP-26 is one of the small agreements that lets different Nostr apps understand the same kind of activity. In everyday terms, it is like agreeing on the shape of a form: once everyone uses the same form for delegated event signing, people can move between apps without losing the meaning of what they created.
Read more in the official 26.md NIP document.