Country code
Country codes are short alphabetic or numeric codes developed to represent countries and dependent areas, for use in data processing and communications. Several different systems have been developed to do this. The most famous of these is ISO 3166. ISO 3166 defines two and three-letter country codes, and three-digit numeric codes, for most of the countries and dependent areas in the world. The two-letter codes from ISO 3166 are used as the basis for country code top-level domain names (ccTLDs) on the Internet. (If you are looking for a list of country codes used on the Internet, see Internet ccTLDs.)
Other country coding systems in use include the FIPS two-letter country codes used by the US government and in the CIA World Factbook, the coding system for car licenses plates under the 1949 and 1968 United Nations Road Traffic Conventions, and the E.164 international dialling codes developed by the ITU.
The developers of ISO 3166 intended that in time it would replace other coding systems in existence. It is used as the basis for many other standards, including ISO 4217 currency codes, International Bank Account Numbers, the ISO 6166 International securities identification numbering (ISIN) system, ISO 7372, ISO 9375, the ISO/IEC 7501-1 machine readable travel documents standard, UN/LOCODE (United Nations Economic Commission for Europe Recommendation 16, for encoding names of ports), and WIPO standard ST.3 (for encoding country which issued a patent or trademark).
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