| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 2533 | A Syntax for Describing Media Feature SetsG. Klyne | Proposed Standard | March 1999 |
| 2738 | Corrections to "A Syntax for Describing Media Feature Sets"G. Klyne | Proposed Standard | December 1999 |
| 3261 | SIP: Session Initiation ProtocolJ. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler | Proposed Standard | July 2002 |
| 3263 | Session Initiation Protocol (SIP): Locating SIP ServersJ. Rosenberg, H. Schulzrinne | Proposed Standard | July 2002 |
| 3688 | The IETF XML RegistryM. Mealling | Best Current Practice | January 2004 |
| 3840 | Indicating User Agent Capabilities in the Session Initiation Protocol (SIP)J. Rosenberg, H. Schulzrinne, P. Kyzivat | Proposed Standard | August 2004 |
| 3966 | The tel URI for Telephone NumbersH. Schulzrinne | Proposed Standard | December 2004 |
| 3986 | Uniform Resource Identifier (URI): Generic SyntaxT. Berners-Lee, R. Fielding, L. Masinter | Internet Standard | January 2005 |
| 4648 | The Base16, Base32, and Base64 Data EncodingsS. Josefsson | Proposed Standard | October 2006 |
| 5245 | Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer ProtocolsJ. Rosenberg · obsoleted by RFC 8445, RFC 8839 | Proposed Standard | April 2010 |
| 5280 | Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) ProfileD. Cooper, S. Santesson, S. Farrell, S. Boeyen, R. Housley, W. Polk | Proposed Standard | May 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 |
| 5627 | Obtaining and Using Globally Routable User Agent URIs (GRUUs) in the Session Initiation Protocol (SIP)J. Rosenberg | Proposed Standard | October 2009 |
| 5767 | User-Agent-Driven Privacy Mechanism for SIPM. Munakata, S. Schubert, T. Ohba | Informational | April 2010 |
| 6940 | REsource LOcation And Discovery (RELOAD) Base ProtocolC. Jennings, B. Lowekamp, Ed., E. Rescorla, S. Baset, H. Schulzrinne | Proposed Standard | January 2014 |
| 7841 | RFC Streams, Headers, and BoilerplatesJ. Halpern, Ed., L. Daigle, Ed., O. Kolkman, Ed. | Informational | May 2016 |
| 7890 | Concepts and Terminology for Peer-to-Peer SIP (P2PSIP)D. Bryan, P. Matthews, E. Shim, D. Willis, S. Dawkins | Informational | June 2016 |