Request for Comments (RFC) are a series of documents that describe behaviors, methods, protocols, or ideas related to the interworking of the Internet. The series started in 1969 by Steve Crocker as a simple way of keeping development notes about ARPANET. Today, RFCs are the official record for the Internet protocols and specifications. The Internet Engineering Task Force (IETF) is in charge of publishing and approving new RFCs.

Sub-Series

The RFC series contains three sub-series:

BCP - Best Current Practices

BCP are a sub-series of RFCs that describe best current practices for the Internet community. This series is designed to be a mechanism by which the IETF can endorse technical information. BCP documents, however, are not and can never become official Internet Standards. BCPs were defined in RFC 1818.

FYI - For Your Information

FYIs are a sub-series of RFCs that are designed to provide Internet users with central repository of information about any topics which relate to the Internet. The FYI sub-section was started in March 1990 and lasted until its conclusion in August 2011. FYIs were defined in RFC 1150 and RFC 6360.

STD - Standard

STD are a sub-series of RFCs that are considered an Internet Standard. From RFC 2026: An Internet Standard is characterized by a high degree of technical maturity and by a generally held belief that the specified protocol or service provides significant benefit to the Internet community. STDs were defined in RFC 1310, RFC 1602 Rev 2, RFC 2026 Rev 3, and RFC 6410