Standard or regulation
Tags for Identifying Languages (BCP 47, RFC 5646)
Addison Phillips and Mark Davis, Internet Engineering Task Force (IETF), 2009
Read the originalRead on October 17, 2026
- What it is
- The IETF best current practice that defines the language tags used by browsers, operating systems and speech services, such as en-GB or ar-EG. It defines the language, script, region and variant subtags and the rules for combining them.
- How much weight it carries
- An IETF Best Current Practice, published in 2009 and maintained since, that the web and software platforms follow. It defines the tag format but does not list which regions a dictation product supports.
Facts taken from this source
- BCP 47 says that a region subtag is typically used to indicate variations such as regional dialects or usage, or region-specific spelling conventions.
“Typically, a region subtag is used to indicate variations such as regional dialects or usage, or region-specific spelling conventions.” (Section 2.2.4 Region Subtag)