http://www.rfc-editor.org/rfc/rfc1041.txt
RFC 1041: Telnet 3270 regime option, Y. Rekhter1988-01-01T23:00:00-00:00This RFC specifies a proposed standard for the Internet community. Hosts on the Internet that want to support 3270 data stream within the Telnet protocol, are expected to adopt and implement this standard.