language
Code for Identifying Languages
2008-02-22
Provides codes for identifying all known languages, both living and
extinct, from the ISO 639 family of international standards (Parts 1, 2, and 3).
It is used with Language to indicate a language the resource is written or spoken
in. It is used with Subject to indicate a language the resource is about.
dc:language
dc:subject
http://www.language-archives.org/REC/language.html