| 2045 | Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message BodiesN. Freed, N. Borenstein | Draft Standard | November 1996 |
| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 3023 | XML Media TypesM. Murata, S. St. Laurent, D. Kohn · obsoleted by RFC 7303 | Proposed Standard | January 2001 |
| 3261 | SIP: Session Initiation ProtocolJ. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler | Proposed Standard | July 2002 |
| 3262 | Reliability of Provisional Responses in Session Initiation Protocol (SIP)J. Rosenberg, H. Schulzrinne | Proposed Standard | July 2002 |
| 3263 | Session Initiation Protocol (SIP): Locating SIP ServersJ. Rosenberg, H. Schulzrinne | Proposed Standard | July 2002 |
| 3264 | An Offer/Answer Model with Session Description Protocol (SDP)J. Rosenberg, H. Schulzrinne | Proposed Standard | July 2002 |
| 3311 | The Session Initiation Protocol (SIP) UPDATE MethodJ. Rosenberg | Proposed Standard | October 2002 |
| 3525 | Gateway Control Protocol Version 1C. Groves, Ed., M. Pantaleo, Ed., T. Anderson, Ed., T. Taylor, Ed. · obsoleted by RFC 5125 | Historic | June 2003 |
| 3550 | RTP: A Transport Protocol for Real-Time ApplicationsH. Schulzrinne, S. Casner, R. Frederick, V. Jacobson | Internet Standard | July 2003 |
| 3629 | UTF-8, a transformation format of ISO 10646F. Yergeau | Internet Standard | November 2003 |
| 3688 | The IETF XML RegistryM. Mealling | Best Current Practice | January 2004 |
| 3725 | Best Current Practices for Third Party Call Control (3pcc) in the Session Initiation Protocol (SIP)J. Rosenberg, J. Peterson, H. Schulzrinne, G. Camarillo | Best Current Practice | April 2004 |
| 3840 | Indicating User Agent Capabilities in the Session Initiation Protocol (SIP)J. Rosenberg, H. Schulzrinne, P. Kyzivat | Proposed Standard | August 2004 |
| 3841 | Caller Preferences for the Session Initiation Protocol (SIP)J. Rosenberg, H. Schulzrinne, P. Kyzivat | Proposed Standard | August 2004 |
| 4145 | TCP-Based Media Transport in the Session Description Protocol (SDP)D. Yon, G. Camarillo | Proposed Standard | September 2005 |
| 4288 | Media Type Specifications and Registration ProceduresN. Freed, J. Klensin · obsoleted by RFC 6838 | Best Current Practice | December 2005 |
| 4566 | SDP: Session Description ProtocolM. Handley, V. Jacobson, C. Perkins · obsoleted by RFC 8866 | Proposed Standard | July 2006 |
| 4574 | The Session Description Protocol (SDP) Label AttributeO. Levin, G. Camarillo | Proposed Standard | August 2006 |
| 4855 | Media Type Registration of RTP Payload FormatsS. Casner | Proposed Standard | February 2007 |
| 5125 | Reclassification of RFC 3525 to HistoricT. Taylor | Informational | February 2008 |
| 5167 | Media Server Control Protocol RequirementsM. Dolly, R. Even | Informational | March 2008 |
| 5226 | Guidelines for Writing an IANA Considerations Section in RFCsT. Narten, H. Alvestrand · obsoleted by RFC 8126 | Best Current Practice | May 2008 |
| 5234 | Augmented BNF for Syntax Specifications: ABNFD. Crocker, Ed., P. Overell | Internet Standard | January 2008 |
| 5246 | The Transport Layer Security (TLS) Protocol Version 1.2T. Dierks, E. Rescorla · obsoleted by RFC 8446, RFC 9846 | Proposed Standard | August 2008 |
| 5626 | Managing Client-Initiated Connections in the Session Initiation Protocol (SIP)C. Jennings, Ed., R. Mahy, Ed., F. Audet, Ed. | Proposed Standard | October 2009 |
| 5741 | RFC Streams, Headers, and BoilerplatesL. Daigle, Ed., O. Kolkman, Ed., IAB · obsoleted by RFC 7841 | Informational | December 2009 |
| 5751 | Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.2 Message SpecificationB. Ramsdell, S. Turner · obsoleted by RFC 8551 | Proposed Standard | January 2010 |
| 5922 | Domain Certificates in the Session Initiation Protocol (SIP)V. Gurbani, S. Lawrence, A. Jeffrey | Proposed Standard | June 2010 |