A standard for representing names of countries, dependent territories, special areas of geographical interest, and their principal subdivisions (e.g., provinces or states) by assigning to each a two-letter, three-letter, and three-digit abbreviation, e.g., `CN`, `CHN`, and `156` for Chinese, `IL`, `ISR`, and `376` for Israel, `PM`, `SPM`, and `666` for Saint Pierre etc.