Request for comment - traditionally, the way standards were implemented on the web. Someone proposes a set of rules for a certain action, others comment on it, and it's eventually finalized. Applications will often say they conform to RFC something-or-other to prove they interoperate with basic standards. The RFC most people use daily is RFC2616, aka HTTP/1.1
Someone needs to draft an RFC for a stab-idiot-IRC-users-in-the-face protocol.