The standard means within the Domain Name System protocol for maintaining coherence among a zone's authoritative name servers consists of three mechanisms. Authoritative Transfer (AXFR) is one of the mechanisms and is defined in RFC 1034 and RFC 1035.

Every version of the FTP specification has added a few new commands, with the early ones summarized in RFC 959. RFC 2389 established a mechanism for specifying and negotiating FTP extensions. The number of extensions, both those supported by the mechanism and some that are not, continues to increase. An IANA registry of FTP Command and Feature names is established to reduce the likelihood of conflict of names and the consequent ambiguity. This specification establishes that registry.