Request for Comments (RFC)

A Request for Comments (RFC) is a numbered document, which includes appraisals, descriptions and definitions of online protocols, concepts, methods and programmes. RFCs are administered by the IETF (Internet Engineering Task Force). A large part of the standards used online are published in RFCs. Some fundamental RFCs were officially adopted as standards. Nevertheless, a large proportion of RFCs are not granted “Standard” status, but are still used as such all over the world. The reason behind this is that the individuals or groups working on an RFC primarily use their time to improve protocols, and not for the standardisation process.

The first published RFCs open up technical matters for discussion. But a Request for Comments can only be called such when it has achieved general acceptance and developed into a quasi-standard. The numbering of an RFC can change if, for example, a new document emerges with significant alterations or amendments, or that is a synthesis of various previous documents.

The formal nature of a Request for Comments

Composing an RFC is a very formalised process. How to write an RFC is described in RFC 2223. RFC 2119 sets out what significance is attached to certain terms, such as “must” or “must not”. This aims to avoid any misinterpretations. How to put character strings together is also clearly defined. If an RFC ends up being published, it can no longer be amended. It can only be replaced by an updated RFC.

The significance of the status of an RFC

Every Request for Comments is attributed a certain status. An RFC is “informational” if it contains information or an idea for the online community. An “experimental” RFC is for the purposes of experimentation, or represents the initial stages of an eventual standard. Other possible statuses include “draft” standard (for evaluation), “proposed” standard (a proposal for a standard), “standard” (an official standard) or “historic” (no longer used). RFCs with the status “required” must be complied with immediately, and “recommended” or “suggested” RFCs are simply recommendations. The use of “elective” RFCs is at the discretion of the individual user.