ISO 3166-2:IO
ISO 3166-2:IO is the entry for the
states) of all countries coded in ISO 3166-1
.
Currently no ISO 3166-2 codes are defined in the entry for the British Indian Ocean Territory. The territory has no defined subdivisions.
The British Indian Ocean Territory is officially assigned the ISO 3166-1 alpha-2 code IO. Diego Garcia, its largest island, is exceptionally reserved the ISO 3166-1 alpha-2 code DG on the request of the International Telecommunication Union.