RFC1873: Message/External-Body Content-ID Access Type
Network Working Group E. Levinson Request for Comments: 1873 Accurate Information Systems, Inc. Category: Experimental J. Clark December 1995 ...
RFC2110: MIME E-mail Encapsulation of Aggregate Documents, such as HTML (MHTML)
Network Working Group J. Palme Request for Comments: 2110 Stockholm University/KTH Category: Standards Track A. Hopmann Microsoft Corporation ...
RFC8262: Content-ID Header Field in the Session Initiation Protocol (SIP)
Internet Engineering Task Force (IETF) C. Holmberg Request for Comments: 8262 I. Sedlacek Updates: 5368, 5621, 6442 Ericsson Category: Standards Track October 2017 IS...