https://datatracker.ietf.org/doc/draft-ietf-openpgp-multsig/02/
draft-ietf-openpgp-multsig-02 - Multiple Signatures using Security Multiparts
This document describes how the Security Multiparts defined in RFC 1847 [1] can be used to transport multiple digital signatures. This draft is being discussed...
draftietfopenpgpmultiplesignatures