A top-level domain (TLD) is one of the domains at the highest level in the hierarchical Domain Name System of the Internet after the root domain. The top-level domain names are installed in the root zone of the name space. For all domains in lower levels, it is the last part of the domain name, that is, the last non-empty label of a fully qualified domain name. For example, in the domain name www.example.com, the top-level domain is .com. Responsibility for management of most top-level domains is delegated to specific organizations by the ICANN, an Internet multi-stakeholder community, which operates the Internet Assigned Numbers Authority (IANA), and is in charge of maintaining the DNS root zone.
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 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.
.de is the country code top-level domain (ccTLD) for Germany. DENIC does not require specific second-level domains, and there are no official ccSLDs under .de ccTLD, as it is the case with the .uk domain range which until 2014 required .co.uk domain for example.
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.
.an was the Internet country code top-level domain (ccTLD) for the former Netherlands Antilles. It was administered by the University of the Netherlands Antilles. The domain was phased out after the Netherlands Antilles were dissolved in 2010. As of November 2010 the .an domain remained live with over 800 domains registered under .an, including secondary levels. On 31 July 2015, use of the domain was discontinued.
.tl is the current country code top-level domain (ccTLD) for East Timor (Timor-Leste). It is administered through the Council of Country Code Administrators (CoCCA) and second-level registration is available through resellers worldwide with no local presence requirement.
.cs was for several years the country code top-level domain (ccTLD) for Czechoslovakia. However, the country split into the Czech Republic and Slovakia in 1993, and the two new countries were soon assigned their own ccTLDs: .cz and .sk respectively. The use of .cs was gradually phased out, and the ccTLD was deleted some time around January 1995.
.yu was the Internet country code top-level domain (ccTLD) that was assigned to SFR Yugoslavia in 1989 and was mainly used by Serbia and Montenegro and its two successor states. After Montenegro and Serbia acquired separate .me and .rs domains in 2007, a transition period started, and the .yu domain finally expired in 2010.
.mq is the Internet country code top-level domain (ccTLD) for Martinique.
.na is the Internet country code top-level domain (ccTLD) for Namibia corresponding to the two letter code from the ISO-3166 standard.
.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.
.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.
ISO 3166-2:SJ is the entry for Svalbard and Jan Mayen in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO). The standard defines codes for names of principal subdivisions of all countries coded in ISO 3166-1. Svalbard and Jan Mayen does not exist as an administrative region, but rather consists of two separate parts of Norway under separate jurisdictions—Svalbard and Jan Mayen. Further subdivision for Svalbard and Jan Mayen occurs under Norway's entry, ISO 3166-2:NO, namely NO-21 for Svalbard and NO-22 for Jan Mayen. There are currently no ISO 3166-2 codes for Svalbard and Jan Mayen.
.sx is the country code top-level domain (ccTLD) in the Domain Name System of the Internet for Sint Maarten.
.bq is designated—but not in use—as the Internet country code top-level domain (ccTLD) for Bonaire, Sint Eustatius and Saba following the assignment on December 15, 2010, by the ISO 3166 Maintenance Agency of BQ as the ISO 3166-1 alpha-2 to the area. This decision followed the dissolution of the Netherlands Antilles and new status of the Caribbean Netherlands as public bodies of the Netherlands on October 10, 2010.
.ss is the designated country code top-level domain (ccTLD) for South Sudan in the Domain Name System of the Internet. It is derived from the ISO 3166-1 alpha-2 code for South Sudan, which is SS. According to CIO East Africa, the TLD was allocated on 10 August 2011 following the country's declaration of independence from Sudan. The TLD was registered on 31 August 2011, but not added to the DNS root zone and was thus not operational. It was approved at the ICANN Board meeting on 27 January 2019 and was added to the DNS root zone on 2 February 2019.
.xk is a temporary, unofficial country code top-level domain for Kosovo, assigned under the United Nations Security Council Resolution 1244 in 1999.
East Germany 