Language Tags 2025-04-02 Expert Review Doug Ewell Registration requests should be submitted to the ietf-languages@ietf.org mailing list. For more information, see . The format of the registry is explained in Section 3 and Section 3.1 of . When referring to language tags in specifications, please refer to . Language subtag registration forms are available in the Language Subtag Registration Form Archive. IETF Review or IESG Approval While registration requires IESG approval or an IETF Stream RFC, the maintaining authority for an extension can submit changes to contact information and/or URLs directly to IANA, as described in . Registry closed This registry is obsolete and has been replaced by the Language Subtag Registry, as described in . Language tag registration forms are available in the Language Tag Registration Form Archive.