| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 2617 | HTTP Authentication: Basic and Digest Access AuthenticationJ. Franks, P. Hallam-Baker, J. Hostetler, S. Lawrence, P. Leach, A. Luotonen, L. Stewart · obsoleted by RFC 7235, RFC 7615, RFC 7616, RFC 7617 | Draft Standard | June 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 |
| 3310 | Hypertext Transfer Protocol (HTTP) Digest Authentication Using Authentication and Key Agreement (AKA)A. Niemi, J. Arkko, V. Torvinen | Informational | September 2002 |
| 3588 | Diameter Base ProtocolP. Calhoun, J. Loughney, E. Guttman, G. Zorn, J. Arkko · obsoleted by RFC 6733 | Proposed Standard | September 2003 |
| 3680 | A Session Initiation Protocol (SIP) Event Package for RegistrationsJ. Rosenberg | Proposed Standard | March 2004 |
| 3880 | Call Processing Language (CPL): A Language for User Control of Internet Telephony ServicesJ. Lennox, X. Wu, H. Schulzrinne | Proposed Standard | November 2004 |
| 4004 | Diameter Mobile IPv4 ApplicationP. Calhoun, T. Johansson, C. Perkins, T. Hiller, Ed., P. McCann | Proposed Standard | August 2005 |
| 4005 | Diameter Network Access Server ApplicationP. Calhoun, G. Zorn, D. Spence, D. Mitton · obsoleted by RFC 7155 | Proposed Standard | August 2005 |
| 4006 | Diameter Credit-Control ApplicationH. Hakala, L. Mattila, J-P. Koskinen, M. Stura, J. Loughney · obsoleted by RFC 8506 | Proposed Standard | August 2005 |
| 4346 | The Transport Layer Security (TLS) Protocol Version 1.1T. Dierks, E. Rescorla · obsoleted by RFC 5246 | Historic | April 2006 |
| 4590 | RADIUS Extension for Digest AuthenticationB. Sterman, D. Sadolevsky, D. Schwartz, D. Williams, W. Beck · obsoleted by RFC 5090 | Proposed Standard | July 2006 |