https://app.knowbase.one/vault/rfc/docid/6440
RFC5922: Domain Certificates in the Session Initiation Protocol (SIP)
Internet Engineering Task Force (IETF) V. Gurbani Request for Comments: 5922 Bell Laboratories, Alcatel-Lucent Updates: 3261 S. Lawrence Category: Standards Track ISSN: 2070-1721 ...