| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 2131 | Dynamic Host Configuration ProtocolR. Droms | Draft Standard | March 1997 |
| 2277 | IETF Policy on Character Sets and LanguagesH. Alvestrand | Best Current Practice | January 1998 |
| 2326 | Real Time Streaming Protocol (RTSP)H. Schulzrinne, A. Rao, R. Lanphier · obsoleted by RFC 7826 | Proposed Standard | April 1998 |
| 2434 | Guidelines for Writing an IANA Considerations Section in RFCsT. Narten, H. Alvestrand · obsoleted by RFC 5226 | Best Current Practice | October 1998 |
| 2543 | SIP: Session Initiation ProtocolM. Handley, H. Schulzrinne, E. Schooler, J. Rosenberg · obsoleted by RFC 3261, RFC 3262, RFC 3263, RFC 3264, RFC 3265 | Proposed Standard | March 1999 |
| 2616 | Hypertext Transfer Protocol -- HTTP/1.1R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P. Leach, T. Berners-Lee · obsoleted by RFC 7230, RFC 7231, RFC 7232, RFC 7233, RFC 7234, RFC 7235 | Draft Standard | June 1999 |
| 3173 | IP Payload Compression Protocol (IPComp)A. Shacham, B. Monsour, R. Pereira, M. Thomas | Proposed Standard | September 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 |
| 3264 | An Offer/Answer Model with Session Description Protocol (SDP)J. Rosenberg, H. Schulzrinne | Proposed Standard | July 2002 |
| 3265 | Session Initiation Protocol (SIP)-Specific Event NotificationA. B. Roach · obsoleted by RFC 6665 | Proposed Standard | July 2002 |
| 3311 | The Session Initiation Protocol (SIP) UPDATE MethodJ. Rosenberg | Proposed Standard | October 2002 |
| 3329 | Security Mechanism Agreement for the Session Initiation Protocol (SIP)J. Arkko, V. Torvinen, G. Camarillo, A. Niemi, T. Haukka | Proposed Standard | January 2003 |
| 3427 | Change Process for the Session Initiation Protocol (SIP)A. Mankin, S. Bradner, R. Mahy, D. Willis, J. Ott, B. Rosen · obsoleted by RFC 5727 | Best Current Practice | December 2002 |
| 3515 | The Session Initiation Protocol (SIP) Refer MethodR. Sparks | Proposed Standard | April 2003 |
| 3665 | Session Initiation Protocol (SIP) Basic Call Flow ExamplesA. Johnston, S. Donovan, R. Sparks, C. Cunningham, K. Summers | Best Current Practice | January 2004 |
| 3680 | A Session Initiation Protocol (SIP) Event Package for RegistrationsJ. Rosenberg | Proposed Standard | March 2004 |
| 3968 | The Internet Assigned Number Authority (IANA) Header Field Parameter Registry for the Session Initiation Protocol (SIP)G. Camarillo | Best Current Practice | December 2004 |
| 3969 | The Internet Assigned Number Authority (IANA) Uniform Resource Identifier (URI) Parameter Registry for the Session Initiation Protocol (SIP)G. Camarillo | Best Current Practice | December 2004 |
| 3986 | Uniform Resource Identifier (URI): Generic SyntaxT. Berners-Lee, R. Fielding, L. Masinter | Internet Standard | January 2005 |
| 4028 | Session Timers in the Session Initiation Protocol (SIP)S. Donovan, J. Rosenberg | Proposed Standard | May 2005 |
| 4101 | Writing Protocol ModelsE. Rescorla, IAB | Informational | June 2005 |
| 4234 | Augmented BNF for Syntax Specifications: ABNFD. Crocker, Ed., P. Overell · obsoleted by RFC 5234 | Draft Standard | October 2005 |
| 4321 | Problems Identified Associated with the Session Initiation Protocol's (SIP) Non-INVITE TransactionR. Sparks | Informational | January 2006 |
| 4483 | A Mechanism for Content Indirection in Session Initiation Protocol (SIP) MessagesE. Burger, Ed. | Proposed Standard | May 2006 |