IETF language tag
An IETF language tag is a standard identifier for a human language or dialect. It is a short string of text; an example is "en-US".
A language tag consists of a sequence of hyphen-separated subtags, which define and refine the language.
Registration of subtags is handled by IANA. Language tags are no longer registered directly.
[TODO: What exactly is the relationship between this and ISO 639?]
- RFC 5646: Tags for Identifying Languages
- RFC 4647: Matching of Language Tags
- BCP 47: Tags for Identifying Languages
- RFC 1766: Tags for the Identification of Languages
- RFC 3066: Tags for the Identification of Languages
- RFC 4646: Tags for Identifying Languages