Similar to ISO_3166-3
ISO 3166-2:WF
ISO 3166-2:WFISO 3166-2:WS
ISO 3166-2:WSISO 3166-2:YE
ISO 3166-2:YEISO 3166-2:YT
ISO 3166-2:YTISO 3166-2:YU
ISO 3166-2:ZA
ISO 3166-2:ZAISO 3166-2:ZM
ISO 3166-2:ZMISO 3166-2:ZW
ISO 3166-2:ZW
XK (ユーザ割り当てコード)
XK (user assigned code)