TDG 8 for Language Codes facilitates the inclusion of language codes from ISO 639 (all parts) in the framework of the DCR. These codes [will] reside in the ISO Concept Database and are maintained according to ISO Standards as Databases procedures (ISO Supplement to the ISO/IEC Directives, Annex ST). These codes also involve interaction with ISO 3166 country codes and ISO 15924 script codes.