# Japanese community key

The Japanese municipality key ( Japanese 全国地方 公共 団 体 コ ー ド , zenkoku chihō kōkyō dantai kōdo , German code of the local authorities of the whole country ) is a five- or, with a check digit , six-digit sequence to identify regional authorities in Japan . Its function is comparable to the official municipality key in Germany and Austria.

The Japanese community key was introduced in 1968 by the then Japanese Ministry of Self-Government (now the Ministry of Internal Affairs and Communications ), adopted by the Administrative Oversight Authority in 1970, and has been the basis for censuses and official statistics in Japan ever since.

## construction

The structure of the community key is abcde-f . The first two digits ab designate the Japanese prefecture beginning with Hokkaidō in the north (01) to Okinawa in the south (47) and correspond to the respective code in ISO 3166-2: JP . If the key only refers to the prefecture, the following digits are cde zeros.

The third digit c is 1 for the cities and districts of Tokyo determined by government decree, 2 for the other large cities ( , shi ) and 3 for the small towns ( , machi or chō ) and villages ( , mura or son ) to 7, and for special purpose associations 8. The state land surveying office ( Kokudo Chiriin ) also uses regional authority keys for former districts ( gun ) , these also have 3 to 7 as the third digit and are grouped with the districts belonging to municipalities.

The calculation of the check digit f is carried out according to the calculation rule . ${\ displaystyle f = 11- \ left (6a + 5b + 4c + 3d + 2e \ right) \ mod 11}$