| 791 | Internet ProtocolJ. Postel | Internet Standard | September 1981 |
| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 2244 | ACAP -- Application Configuration Access ProtocolC. Newman, J. G. Myers | Proposed Standard | November 1997 |
| 2277 | IETF Policy on Character Sets and LanguagesH. Alvestrand | Best Current Practice | January 1998 |
| 2460 | Internet Protocol, Version 6 (IPv6) SpecificationS. Deering, R. Hinden · obsoleted by RFC 8200 | Draft Standard | December 1998 |
| 2782 | A DNS RR for specifying the location of services (DNS SRV)A. Gulbrandsen, P. Vixie, L. Esibov | Proposed Standard | February 2000 |
| 2831 | Using Digest Authentication as a SASL MechanismP. Leach, C. Newman · obsoleted by RFC 6331 | Historic | May 2000 |
| 3454 | Preparation of Internationalized Strings ("stringprep")P. Hoffman, M. Blanchet · obsoleted by RFC 7564 | Proposed Standard | January 2003 |
| 3490 | Internationalizing Domain Names in Applications (IDNA)P. Faltstrom, P. Hoffman, A. Costello · obsoleted by RFC 5890, RFC 5891 | Proposed Standard | March 2003 |
| 3501 | INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1M. Crispin · obsoleted by RFC 9051 | Proposed Standard | March 2003 |
| 3629 | UTF-8, a transformation format of ISO 10646F. Yergeau | Internet Standard | November 2003 |
| 3986 | Uniform Resource Identifier (URI): Generic SyntaxT. Berners-Lee, R. Fielding, L. Masinter | Internet Standard | January 2005 |
| 4013 | SASLprep: Stringprep Profile for User Names and PasswordsK. Zeilenga · obsoleted by RFC 7613 | Proposed Standard | March 2005 |
| 4422 | Simple Authentication and Security Layer (SASL)A. Melnikov, Ed., K. Zeilenga, Ed. | Proposed Standard | June 2006 |
| 4510 | Lightweight Directory Access Protocol (LDAP): Technical Specification Road MapK. Zeilenga, Ed. | Proposed Standard | June 2006 |
| 4519 | Lightweight Directory Access Protocol (LDAP): Schema for User ApplicationsA. Sciberras, Ed. | Proposed Standard | June 2006 |
| 4616 | The PLAIN Simple Authentication and Security Layer (SASL) MechanismK. Zeilenga, Ed. | Proposed Standard | August 2006 |
| 4648 | The Base16, Base32, and Base64 Data EncodingsS. Josefsson | Proposed Standard | October 2006 |
| 4752 | The Kerberos V5 ("GSSAPI") Simple Authentication and Security Layer (SASL) MechanismA. Melnikov, Ed. | Proposed Standard | November 2006 |
| 4985 | Internet X.509 Public Key Infrastructure Subject Alternative Name for Expression of Service NameS. Santesson | Proposed Standard | August 2007 |
| 5198 | Unicode Format for Network InterchangeJ. Klensin, M. Padlipsky | Proposed Standard | March 2008 |
| 5228 | Sieve: An Email Filtering LanguageP. Guenther, Ed., T. Showalter, Ed. | Proposed Standard | January 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 |
| 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 |
| 5435 | Sieve Email Filtering: Extension for NotificationsA. Melnikov, Ed., B. Leiba, Ed., W. Segmuller, T. Martin | Proposed Standard | January 2009 |
| 5463 | Sieve Email Filtering: Ihave ExtensionN. Freed | Proposed Standard | March 2009 |
| 5646 | Tags for Identifying LanguagesA. Phillips, Ed., M. Davis, Ed. | Best Current Practice | September 2009 |
| 5741 | RFC Streams, Headers, and BoilerplatesL. Daigle, Ed., O. Kolkman, Ed., IAB · obsoleted by RFC 7841 | Informational | December 2009 |