gpgcompose --help
gpgcompose OPTION --help
gpgcompose is not capable of performing secret key operations on its own. Creation of any OpenPGP object that requires secret key operations (e.g., --signature) will need to speak to an already-running gpg-agent.
Occasionally, gpgcompose will need to look up existing public keys for reference (e.g., --public-key). It will do so in ~/.gnupg/keyring.kbx, or in $GNUPGHOME/keyring.kbx if that variable is set.
RFC 4880, gpg(1), gpg-agent(1), gpg-connect-agent(1)
This manpage was written by Daniel Kahn Gillmor <dkg@fifthhorseman.net>.