"Recommended practice is to use either a non-literal value representing a language from a controlled vocabulary such as ISO 639-2 or ISO 639-3, or a literal value consisting of an IETF Best Current Practice 47 [[IETF-BCP47](https://tools.ietf.org/html/bcp47)] language tag."@en . . . "2008-01-14"^^ . . . "A language of the resource."@en-us . . "2008-01-14" . "Language"@en . "Recommended best practice is to use a controlled vocabulary such as RFC 4646 [RFC4646]."@en-us . "A language of the resource."@en . "Used to link a bibliographic resource to the language used to express it."@en . "Language"@en-us . . . "Used to link a bibliographic resource to the language used to express it."@en . . . . . "2008-01-14" .