Moving RFC 1545 and RFC 1639 to Historic
RFC 1639 and its predecessor - RFC 1545 - specified the way to denote network addresses in the format other than that used with IPv4 when establishing File Transfer Protocol (FTP) data connection. Because of some reasons, described in this document, these commands are now deprecated and their use is discouraged; in order to reflect this it moves RFC 1545 and RFC 1639 to Historic status and obsoletes these two RFCs.