A country code is a short alphanumeric identification code for countries and dependent areas. Its primary use is in data processing and communications. Several identification systems have been developed.
ISO 3166 is a standard published by the International Organization for Standardization (ISO) that defines codes for the names of countries, dependent territories, special areas of geographical interest, and their principal subdivisions. The official name of the standard is Codes for the representation of names of countries and their subdivisions.
ISO 3166-3 is part of the ISO 3166 standard published by the International Organization for Standardization (ISO), and defines codes for country names which have been deleted from ISO 3166-1 since its first publication in 1974. The official name of the standard is Codes for the representation of names of countries and their subdivisions – Part 3: Code for formerly used names of countries. It was first published in 1999.
ISO 3166-1 is a standard defining codes for the names of countries, dependent territories, and special areas of geographical interest. It is the first part of the ISO 3166 standard published by the International Organization for Standardization.
ISO 3166-1 alpha-3 codes are three-letter country codes defined in ISO 3166-1, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), to represent countries, dependent territories, and special areas of geographical interest. They allow a better visual association between the codes and the country names than the two-letter alpha-2 codes. They were first included as part of the ISO 3166 standard in its first edition in 1974.
ISO 3166-1 alpha-2 codes are two-letter country codes defined in ISO 3166-1, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), to represent countries, dependent territories, and special areas of geographical interest. They are the most widely used of the country codes published by ISO, and are used most prominently for the Internet's country code top-level domains. They are also used as country identifiers extending the postal code when appropriate within the international postal system for paper mail, and have replaced the previous one consisting one-letter codes. They were first included as part of the ISO 3166 standard in its first edition in 1974.
Svalbard and Jan Mayen is a statistical designation defined by ISO 3166-1 for a collective grouping of two remote jurisdictions of Norway: Svalbard and Jan Mayen. While the two are combined for the purposes of the International Organization for Standardization (ISO) category, they are not administratively related. This has further resulted in the country code top-level domain .sj being issued for Svalbard and Jan Mayen, and ISO 3166-2:SJ. The United Nations Statistics Division also uses this code, but has named it the Svalbard and Jan Mayen Islands.
ISO 3166-1 numeric codes are three-digit country codes defined in ISO 3166-1, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), to represent countries, dependent territories, and special areas of geographical interest. They are similar to the three-digit country codes developed and maintained by the United Nations Statistics Division, from which they originate in its UN M.49 standard. They were first included as part of the ISO 3166 standard in its second edition in 1981, but they were released by the United Nations Statistics Division since as early as 1970.
A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country, sovereign state, or dependent territory identified with a country code. All ASCII ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs.
.dd was the assigned country code top-level domain (ccTLD) for the German Democratic Republic. It was chosen based on the ISO 3166-1 alpha-2 code for the German Democratic Republic, the letters coming from the German name of the country, Deutsche Demokratische Republik. In accordance with IANA policy, .dd was therefore available to be assigned as the country code top-level domain (ccTLD) for East Germany. However, this was never done, and so .dd was never added to the root nameservers. Its only use was internally in an isolated network among the universities of Jena and Dresden.
.rs is the Internet country code top-level domain (ccTLD) for Serbia. The domain name registry that operates it is the Serbian National Internet Domain Registry (RNIDS). The letters rs stand for Republika Srbija/Република Србија.
ISO 3166-2:RS is the entry for Serbia in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), which defines codes for the names of the principal subdivisions of all countries coded in ISO 3166-1.
.mf is an assigned Internet country code top-level domain (ccTLD) that was to be created for the Collectivity of Saint Martin, but it is currently not in use, as it is not available for registration nor website use of the domain. The decision by the ISO 3166 Maintenance Agency to allocate .mf as the ISO 3166-1 alpha-2 domain for Saint Martin on 21 September 2007, followed the decision of Saint Martin's new status as an Overseas collectivity of France, which took effect on 15 July 2007. Currently Saint Martin uses Guadeloupe's ccTLD, .gp and France's ccTLD, .fr.
The regional indicator symbols are a set of 26 alphabetic Unicode characters (A–Z) intended to be used to encode ISO 3166-1 alpha-2 two-letter country codes in a way that allows optional special treatment.
Country codes for Serbia are short alphanumeric identification codes for country with primary use in data processing and communications.
XK is an ISO 3166-1 alpha-2 equivalent user-assigned code element used to represent Kosovo. Similarly, XKK is an ISO 3166-1 alpha-3 equivalent user-assigned code element for Kosovo.
Kosovo 
