Initialism of remote function call.
"The developer used an rfc to enable a client program to invoke procedures on a server over a network."
In plain English: An RFC is an official document that explains how to use internet standards and protocols so everyone can talk to each other online.
"The developer checked the RFC to see if his new feature was allowed by the protocol standards."
Initialism of Royal Flying Corps (previous title of the Royal Air Force)
"The squadron was originally part of the RFC before it became the Royal Air Force in 1918."