Requests for Comments (RFCs) and Internet Drafts
The IETF's Requests for Comments contain organizational and technical notes about the Internet. They cover various aspects of computer networking, such as protocols, methods, programs, and concepts -- but also conference protocols, opinions, and -- sometimes -- humour. The first RFC was published in 1969, but the number has since grown to several thousand. RFC 2555 presents a history of RFCs.
RFCs that have been published are not subsequently modified. Minor corrections or addenda are added as errata; if a major correction becomes necessary, a new RFC with a new number replaces the old one. The old RFC then references the number of the new one, such as RFC 821.