Variable: LANGUAGE_TAG_PATTERN

const LANGUAGE_TAG_PATTERN: "^[a-z]{2,3}(?:-[A-Z][a-z]{3})?(?:-(?:[A-Z]{2}|[0-9]{3}))?$" = '^[a-z]{2,3}(?:-[A-Z][a-z]{3})?(?:-(?:[A-Z]{2}|[0-9]{3}))?$'

Defined in: packages/contracts/src/schemas/governance-metamodel.ts:220

A BCP 47 language tag in its canonical case, limited to language, an optional script and an optional region: en, ar, ar-SA, zh-Hant-TW. Variants, extensions and private-use subtags are refused: a framework names the languages it is official in, and one spelling per language means comparing two tags is comparing two strings.