http://www.rfc-editor.org/rfc/rfc2957.txt
RFC 2957: The application/whoispp-query Content-Type, L. Daigle, P. Faltstrom2000-10-01T23:00:00-00:00The intention of this document, in conjunction with RFC 2958, is to enable MIME-enabled mail software, and other systems using Internet media types, to carry out Whois++ transactions. This memo provides information for the Internet community.