RFC

From Linux 101, The beginner's guide to all things Linux.

Request For Comments or RFCs are very important documents that outline protocols and standards. They are usually written by a group of individuals and can span into hundreds of pages. They discuss each aspect of the protocol or standard to through its entirety, attempting to answer all possible questions on a subject.

RFCs are refered to by number -- for example RFC 1459 is for Internet Relay Chat (IRC) protocol. Sometimes protcols are updated or extended upon, so it's always best to use the numbers instead of the titles.