| 522 | Traffic Statistics (May 1973)A.M. McKenzie | Unknown | June 1973 |
| 1035 | Domain names - implementation and specificationP. Mockapetris | Internet Standard | November 1987 |
| 1122 | Requirements for Internet Hosts - Communication LayersR. Braden, Ed. | Internet Standard | October 1989 |
| 1918 | Address Allocation for Private InternetsY. Rekhter, B. Moskowitz, D. Karrenberg, G. J. de Groot, E. Lear | Best Current Practice | February 1996 |
| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 2311 | S/MIME Version 2 Message SpecificationS. Dusse, P. Hoffman, B. Ramsdell, L. Lundblade, L. Repka | Historic | March 1998 |
| 2388 | Returning Values from Forms: multipart/form-dataL. Masinter · obsoleted by RFC 7578 | Proposed Standard | August 1998 |
| 2585 | Internet X.509 Public Key Infrastructure Operational Protocols: FTP and HTTPR. Housley, P. Hoffman | Proposed Standard | May 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 |
| 3023 | XML Media TypesM. Murata, S. St. Laurent, D. Kohn · obsoleted by RFC 7303 | Proposed Standard | January 2001 |
| 3174 | US Secure Hash Algorithm 1 (SHA1)D. Eastlake 3rd, P. Jones | Informational | September 2001 |
| 3339 | Date and Time on the Internet: TimestampsG. Klyne, C. Newman | Proposed Standard | July 2002 |
| 3447 | Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1J. Jonsson, B. Kaliski · obsoleted by RFC 8017 | Informational | February 2003 |
| 3629 | UTF-8, a transformation format of ISO 10646F. Yergeau | Internet Standard | November 2003 |
| 3688 | The IETF XML RegistryM. Mealling | Best Current Practice | January 2004 |
| 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 |
| 4086 | Randomness Requirements for SecurityD. Eastlake 3rd, J. Schiller, S. Crocker | Best Current Practice | June 2005 |
| 4145 | TCP-Based Media Transport in the Session Description Protocol (SDP)D. Yon, G. Camarillo | Proposed Standard | September 2005 |
| 4279 | Pre-Shared Key Ciphersuites for Transport Layer Security (TLS)P. Eronen, Ed., H. Tschofenig, Ed. | Proposed Standard | December 2005 |
| 4340 | Datagram Congestion Control Protocol (DCCP)E. Kohler, M. Handley, S. Floyd | Proposed Standard | March 2006 |
| 4395 | Guidelines and Registration Procedures for New URI SchemesT. Hansen, T. Hardie, L. Masinter · obsoleted by RFC 7595 | Best Current Practice | February 2006 |
| 4648 | The Base16, Base32, and Base64 Data EncodingsS. Josefsson | Proposed Standard | October 2006 |
| 4787 | Network Address Translation (NAT) Behavioral Requirements for Unicast UDPF. Audet, Ed., C. Jennings | Best Current Practice | January 2007 |
| 4960 | Stream Control Transmission ProtocolR. Stewart, Ed. · obsoleted by RFC 9260 | Proposed Standard | September 2007 |
| 5054 | Using the Secure Remote Password (SRP) Protocol for TLS AuthenticationD. Taylor, T. Wu, N. Mavrogiannopoulos, T. Perrin | Informational | November 2007 |
| 5095 | Deprecation of Type 0 Routing Headers in IPv6J. Abley, P. Savola, G. Neville-Neil | Proposed Standard | December 2007 |
| 5201 | Host Identity ProtocolR. Moskowitz, P. Nikander, P. Jokela, Ed., T. Henderson · obsoleted by RFC 7401 | Experimental | April 2008 |
| 5226 | Guidelines for Writing an IANA Considerations Section in RFCsT. Narten, H. Alvestrand · obsoleted by RFC 8126 | Best Current Practice | May 2008 |
| 5245 | Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer ProtocolsJ. Rosenberg · obsoleted by RFC 8445, RFC 8839 | Proposed Standard | April 2010 |
| 5246 | The Transport Layer Security (TLS) Protocol Version 1.2T. Dierks, E. Rescorla · obsoleted by RFC 8446, RFC 9846 | Proposed Standard | August 2008 |
| 5272 | Certificate Management over CMS (CMC)J. Schaad, M. Myers · obsoleted by RFC 10002 | Proposed Standard | June 2008 |
| 5273 | Certificate Management over CMS (CMC): Transport ProtocolsJ. Schaad, M. Myers · obsoleted by RFC 10003 | Proposed Standard | June 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 |
| 5389 | Session Traversal Utilities for NAT (STUN)J. Rosenberg, R. Mahy, P. Matthews, D. Wing · obsoleted by RFC 8489 | Proposed Standard | October 2008 |
| 5405 | Unicast UDP Usage Guidelines for Application DesignersL. Eggert, G. Fairhurst · obsoleted by RFC 8085 | Best Current Practice | November 2008 |
| 5694 | Peer-to-Peer (P2P) Architecture: Definition, Taxonomies, Examples, and ApplicabilityG. Camarillo, Ed., IAB | Informational | November 2009 |
| 5741 | RFC Streams, Headers, and BoilerplatesL. Daigle, Ed., O. Kolkman, Ed., IAB · obsoleted by RFC 7841 | Informational | December 2009 |
| 5765 | Security Issues and Solutions in Peer-to-Peer Systems for Realtime CommunicationsH. Schulzrinne, E. Marocco, E. Ivov | Informational | February 2010 |
| 5766 | Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN)R. Mahy, P. Matthews, J. Rosenberg · obsoleted by RFC 8656 | Proposed Standard | April 2010 |
| 5785 | Defining Well-Known Uniform Resource Identifiers (URIs)M. Nottingham, E. Hammer-Lahav · obsoleted by RFC 8615 | Proposed Standard | April 2010 |
| 5952 | A Recommendation for IPv6 Address Text RepresentationS. Kawamura, M. Kawashima | Proposed Standard | August 2010 |
| 6079 | HIP BONE: Host Identity Protocol (HIP) Based Overlay Networking Environment (BONE)G. Camarillo, P. Nikander, J. Hautakorpi, A. Keranen, A. Johnston | Experimental | January 2011 |
| 6091 | Using OpenPGP Keys for Transport Layer Security (TLS) AuthenticationN. Mavrogiannopoulos, D. Gillmor | Informational | February 2011 |
| 6234 | US Secure Hash Algorithms (SHA and SHA-based HMAC and HKDF)D. Eastlake 3rd, T. Hansen | Informational | May 2011 |
| 6298 | Computing TCP's Retransmission TimerV. Paxson, M. Allman, J. Chu, M. Sargent | Proposed Standard | June 2011 |
| 6347 | Datagram Transport Layer Security Version 1.2E. Rescorla, N. Modadugu · obsoleted by RFC 9147 | Proposed Standard | January 2012 |
| 6544 | TCP Candidates with Interactive Connectivity Establishment (ICE)J. Rosenberg, A. Keranen, B. B. Lowekamp, A. B. Roach | Proposed Standard | March 2012 |
| 7086 | Host Identity Protocol-Based Overlay Networking Environment (HIP BONE) Instance Specification for REsource LOcation And Discovery (RELOAD)A. Keranen, G. Camarillo, J. Maenpaa | Experimental | January 2014 |