Currently for Japan, ISO 3166-2 codes are defined for 47 prefectures.
Each code consists of two parts, separated by a hyphen.
The first part is JP, the ISO 3166-1 alpha-2 code of Japan.
The second part is two digits (01–47), which is the Japanese Industrial Standard JIS X 0401 code of the prefecture.
The codes are assigned roughly from north to south.