Matching of Language Tags
This document describes a syntax, called a "language-range", for specifying items in a user's language preferences, called a "language priority list". It also describes different mechanisms for comparing and matching these to language tags. Two kinds of matching mechanisms, filtering and lookup, are defined. Filtering produces a (potentially empty) set of language tags, whereas lookup produces a single language tag. Possible applications include language negotiation or content selection. This document, in combination with RFC 3066bis (Ed.: replace "3066bis" with the RFC number assigned to draft-ietf-ltru-registry-14), replaces RFC 3066, which replaced RFC 1766.