| 791 | Internet ProtocolJ. Postel | Internet Standard | September 1981 |
| 1122 | Requirements for Internet Hosts - Communication LayersR. Braden, Ed. | Internet Standard | October 1989 |
| 1321 | The MD5 Message-Digest AlgorithmR. Rivest | Informational | April 1992 |
| 2104 | HMAC: Keyed-Hashing for Message AuthenticationH. Krawczyk, M. Bellare, R. Canetti | Informational | February 1997 |
| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 2460 | Internet Protocol, Version 6 (IPv6) SpecificationS. Deering, R. Hinden · obsoleted by RFC 8200 | Draft Standard | December 1998 |
| 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 |
| 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 |
| 2782 | A DNS RR for specifying the location of services (DNS SRV)A. Gulbrandsen, P. Vixie, L. Esibov | Proposed Standard | February 2000 |
| 2818 | HTTP Over TLSE. Rescorla · obsoleted by RFC 9110 | Informational | May 2000 |
| 2988 | Computing TCP's Retransmission TimerV. Paxson, M. Allman · obsoleted by RFC 6298 | Proposed Standard | November 2000 |
| 3261 | SIP: Session Initiation ProtocolJ. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler | Proposed Standard | July 2002 |
| 3264 | An Offer/Answer Model with Session Description Protocol (SDP)J. Rosenberg, H. Schulzrinne | Proposed Standard | July 2002 |
| 3424 | IAB Considerations for UNilateral Self-Address Fixing (UNSAF) Across Network Address TranslationL. Daigle, Ed., IAB | Informational | November 2002 |
| 3489 | STUN - Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs)J. Rosenberg, J. Weinberger, C. Huitema, R. Mahy · obsoleted by RFC 5389 | Proposed Standard | March 2003 |
| 3629 | UTF-8, a transformation format of ISO 10646F. Yergeau | Internet Standard | November 2003 |
| 4013 | SASLprep: Stringprep Profile for User Names and PasswordsK. Zeilenga · obsoleted by RFC 7613 | Proposed Standard | March 2005 |
| 4107 | Guidelines for Cryptographic Key ManagementS. Bellovin, R. Housley | Best Current Practice | June 2005 |
| 5226 | Guidelines for Writing an IANA Considerations Section in RFCsT. Narten, H. Alvestrand · obsoleted by RFC 8126 | Best Current Practice | May 2008 |