The InternetRequest for Comment document about Tags for the Identification of Languages (ftp://ftp.rfc-editor.org/in-notes/rfc3066.txt). It provides a way to register extensions of codes for language names in ISO 639. The current reviewer of new tags and maintainer of the registry is Michael Everson (http://www.evertype.com/standards/iso639/iana-lang-assignments). An alternative for language codes is the Ethnologue.
... 1979 Hank Snow
1980 Paul Anka
1981 Joni Mitchell
1982 Neil Young
1983 Glenn Gould
1986 Gordon Lightfoot
1987 The Guess Who[?]
1989 The Band
1990 ...