| 1035 | Domain names - implementation and specificationP. Mockapetris | Internet Standard | November 1987 |
| 1939 | Post Office Protocol - Version 3J. Myers, M. Rose | Internet Standard | May 1996 |
| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 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 |
| 2743 | Generic Security Service Application Program Interface Version 2, Update 1J. Linn | Proposed Standard | January 2000 |
| 2818 | HTTP Over TLSE. Rescorla · obsoleted by RFC 9110 | Informational | May 2000 |
| 3492 | Punycode: A Bootstring encoding of Unicode for Internationalized Domain Names in Applications (IDNA)A. Costello | Proposed Standard | March 2003 |
| 3501 | INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1M. Crispin · obsoleted by RFC 9051 | Proposed Standard | March 2003 |
| 3986 | Uniform Resource Identifier (URI): Generic SyntaxT. Berners-Lee, R. Fielding, L. Masinter | Internet Standard | January 2005 |
| 3987 | Internationalized Resource Identifiers (IRIs)M. Duerst, M. Suignard | Proposed Standard | January 2005 |
| 4401 | A Pseudo-Random Function (PRF) API Extension for the Generic Security Service Application Program Interface (GSS-API)N. Williams | Proposed Standard | February 2006 |
| 4422 | Simple Authentication and Security Layer (SASL)A. Melnikov, Ed., K. Zeilenga, Ed. | Proposed Standard | June 2006 |
| 4648 | The Base16, Base32, and Base64 Data EncodingsS. Josefsson | Proposed Standard | October 2006 |
| 5056 | On the Use of Channel Bindings to Secure ChannelsN. Williams | Proposed Standard | November 2007 |
| 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 |
| 5741 | RFC Streams, Headers, and BoilerplatesL. Daigle, Ed., O. Kolkman, Ed., IAB · obsoleted by RFC 7841 | Informational | December 2009 |
| 5801 | Using Generic Security Service Application Program Interface (GSS-API) Mechanisms in Simple Authentication and Security Layer (SASL): The GS2 Mechanism FamilyS. Josefsson, N. Williams | Proposed Standard | July 2010 |
| 5890 | Internationalized Domain Names for Applications (IDNA): Definitions and Document FrameworkJ. Klensin | Proposed Standard | August 2010 |
| 5891 | Internationalized Domain Names in Applications (IDNA): ProtocolJ. Klensin | Proposed Standard | August 2010 |
| 6120 | Extensible Messaging and Presence Protocol (XMPP): CoreP. Saint-Andre | Proposed Standard | March 2011 |
| 6125 | Representation and Verification of Domain-Based Application Service Identity within Internet Public Key Infrastructure Using X.509 (PKIX) Certificates in the Context of Transport Layer Security (TLS)P. Saint-Andre, J. Hodges · obsoleted by RFC 9525 | Proposed Standard | March 2011 |