https://lists.gnupg.org/pipermail/gnupg-devel/2006-October/023330.html
[GPGME] statefulness of gpgme_op_keylist_*
gpgmeop
https://datatracker.ietf.org/doc/html/draft-mccain-keylist-04
draft-mccain-keylist-04
Distributing OpenPGP Key Fingerprints with Signed Keylist Subscriptions (Internet-Draft, 2019)
draftmccain