What is an "RFC" and where do I find them?

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RFC is an acronym for Request for Comments and official documents from the Internet Engineering Task Force (IETF) with an unlimited distribution.  RFC's are numbered in a series and are referred to by numbers.


RFC's contain information for the Internet Community including users and system administrators as well as developers.  Some RFC's describe standardized protocols such as FTP (File Transfer Protocol), SMTP (Simple Mail Transfer Protocol), POP3 (Post Office Protocol 3), IMAP4 (Internet Message Access Protocol 4), and DNS (Domain Name Service).  Sometimes, a protocol is updated by a RFC. 


FTP is based mostly on RFC 959 but is updated and supplemented by


RFC 1639

FTP Operation Over Big Address Records (FOOBAR) 

RFC 2428

FTP Extensions for IPv6 and NATs 

RFC 2389

Feature negotiation mechanism for the File Transfer Protocol 

RFC 2228

FTP Security Extensions 


You can locate many RFC's at http://www.rfc-editor.org/ and the standardization process is described in RFC 2026.


We should also note that sometimes Indy also follows Internet Drafts.  These are working documents are considered works in progress and some drafts do not become standards.  We do this because some features described in the Draft are in common usage or provide a valuable feature.  You can search for Internet Drafts at http://www.ietf.org/.


Occasionally, Indy developers will sometimes implement features and protocols which are not described in RFC's or drafts because we see that something is in common usage and demand and either is in a specification which is readily available or appears to be a de facto standard.  Such things include Gopher+ support, YEnc encoding in Indy 10, RSH, Rexec, and UUEncoding.