| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 3261 | SIP: Session Initiation ProtocolJ. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler | Proposed Standard | July 2002 |
| 3325 | Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted NetworksC. Jennings, J. Peterson, M. Watson | Informational | December 2002 |
| 3372 | Session Initiation Protocol for Telephones (SIP-T): Context and ArchitecturesA. Vemuri, J. Peterson | Best Current Practice | September 2002 |
| 3515 | The Session Initiation Protocol (SIP) Refer MethodR. Sparks | Proposed Standard | April 2003 |
| 3840 | Indicating User Agent Capabilities in the Session Initiation Protocol (SIP)J. Rosenberg, H. Schulzrinne, P. Kyzivat | Proposed Standard | August 2004 |
| 3891 | The Session Initiation Protocol (SIP) "Replaces" HeaderR. Mahy, B. Biggs, R. Dean | Proposed Standard | September 2004 |
| 4474 | Enhancements for Authenticated Identity Management in the Session Initiation Protocol (SIP)J. Peterson, C. Jennings · obsoleted by RFC 8224 | Proposed Standard | August 2006 |
| 4475 | Session Initiation Protocol (SIP) Torture Test MessagesR. Sparks, Ed., A. Hawrylyshen, A. Johnston, J. Rosenberg, H. Schulzrinne | Informational | May 2006 |
| 4648 | The Base16, Base32, and Base64 Data EncodingsS. Josefsson | Proposed Standard | October 2006 |
| 4916 | Connected Identity in the Session Initiation Protocol (SIP)J. Elwell | Proposed Standard | June 2007 |
| 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 |
| 5727 | Change Process for the Session Initiation Protocol (SIP) and the Real-time Applications and Infrastructure AreaJ. Peterson, C. Jennings, R. Sparks | Best Current Practice | March 2010 |
| 5741 | RFC Streams, Headers, and BoilerplatesL. Daigle, Ed., O. Kolkman, Ed., IAB · obsoleted by RFC 7841 | Informational | December 2009 |
| 6086 | Session Initiation Protocol (SIP) INFO Method and Package FrameworkC. Holmberg, E. Burger, H. Kaplan | Proposed Standard | January 2011 |
| 6567 | Problem Statement and Requirements for Transporting User-to-User Call Control Information in SIPA. Johnston, L. Liess | Informational | April 2012 |
| 7044 | An Extension to the Session Initiation Protocol (SIP) for Request History InformationM. Barnes, F. Audet, S. Schubert, J. van Elburg, C. Holmberg | Proposed Standard | February 2014 |
| 7434 | Interworking ISDN Call Control User Information with SIPK. Drage, Ed., A. Johnston | Proposed Standard | January 2015 |