http://www.rfc-editor.org/rfc/rfc1311.txt
RFC 1311: Introduction to the STD Notes, J. Postel1992-03-01T23:00:00-00:00The STDs are a subseries of notes within the RFC series that are the Internet standards. The intent is to identify clearly for the Internet community those RFCs which document Internet standards. [STANDARDS-TRACK]