Acountry code top-level domain (ccTLD) is anInternettop-level domain generally used or reserved for acountry, sovereign state, ordependent territory identified with acountry code. AllASCII ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs.
In 2018, theInternet Assigned Numbers Authority (IANA) began implementinginternationalized country code top-level domains, consisting of language-native characters when displayed in an end-user application. Creation and delegation of ccTLDs is described in RFC 1591, corresponding to ISO 3166-1 alpha-2 country codes. WhilegTLDs have to obey international regulations, ccTLDs are subjected to requirements that are determined by each country's domain name regulation corporation. With over 150 million domain name registrations as of 2022, ccTLDs make up about 40% of the total domain name industry.[1]
Country code extension applications began in 1985. The registered country code extensions in that year included.us (United States),.uk (United Kingdom) and.il (Israel). The registered country code extensions in 1986 included.au (Australia),.de (Germany),.fi (Finland),.fr (France),.is (Iceland),.jp (Japan),.kr (South Korea),.nl (Netherlands) and.se (Sweden). The registered country code extensions in 1987 included.nz (New Zealand),.ch (Switzerland) and.ca (Canada).[2] The registered country code extensions in 1988 included.ie (Ireland).it (Italy),.es (Spain) and.pt (Portugal). The registered country code extensions in 1989 included.in (India) and.yu (Yugoslavia). In the 1990s,.cn (People's Republic of China) and.ru (Russian Federation) were first registered.
There are 308 delegated ccTLDs. The.cn,.tk,.de,.uk,.nl and.ru ccTLDs contain the highest number of domains. The top ten ccTLDs account for more than five-eighths of registered ccTLD domains. There were about 153 million ccTLD domains registered at the end of March 2022.[1]
IANA is responsible for determining an appropriate trustee for each ccTLD. Administration and control are then delegated to that trustee, which is responsible for the policies and operation of the domain. The delegation can be determined from IANA's list of ccTLDs.[3] Individual ccTLDs may have varying requirements and fees for registeringsubdomains. There may be a local-presence requirement (for instance, citizenship or other connection to the ccTLD), as, for example, theAmerican (us),Japanese (jp),Canadian (ca),French (fr) andGerman (de) domains, or registration may be open.
The first registered ccTLD was.us, which was registered in 1985. Later ccTLDs registered in that year included.uk and.il. Then,.au,.de,.fi,.fr,.is,.jp,.kr,.nl and.se were also registered in 1986.[3] In 1987,.nz,.ch,.my and.ca were registered. Later on, in 1988,.ie,.it,.es and.pt were also registered.
As of 20 May 2017, there were 255 country-code top-level domains, purely in the Latin alphabet, using two-character codes. The number was 316 as of June 2020[update], with the addition of internationalized domains.[3]
DNS name of the two-letter country-code top-level domain. They followISO 3166-1 alpha-2, with some exceptions such as ".ac" for Ascension Island, ".eu" for the European Union, or ".uk" for United Kingdom of Great Britain and Northern Ireland instead of ".gb". ISO codesbv,bl,mf,sj,gb, andum are not used for country code top-level domains.
Entity
Country, dependency, or region
Explanation
English name of the country. These are usually domains that arise from native name of the country (e.g..de forDeutschland,German name for Germany).
Notes
General remarks
Registry
Domain name registry operator, sometimes called a network information center (NIC)
InISO 3166-1, Ascension Island falls underSaint Helena, Ascension and Tristan da Cunha's codeSH.AC is an exceptionally reserved ISO 3166-1 code. Commonly used for academic websites, such as universities. However,.ac is not to be confused with the official academic domains used by several countries such as theUnited Kingdom (.ac.uk),India (.ac.in) orIndonesia (.ac.id). Also used in the accounting, consulting, and air-conditioning industries.
Defined by theAntarctic Treaty as everything south oflatitude 60°S. AQ domain names are available to government organizations who are signatories to the Antarctic Treaty and to other registrants who have a physical presence in Antarctica. Domain names can be registered and renewed free of charge.
In some countries, like Norway and Denmark, "AS" or "A/S" is used as an abbreviation for stock-based or limited companies. Such companies will often make use of the domain. Also unofficially used by the Principality ofAsturias, Spain.
Restrictions apply. In general, registrants must have an "Australian presence", and can be registered anywhere between 1 and 5 years.[7] IncludesAshmore and Cartier Islands andCoral Sea Islands. Direct second-level domain registration (marketed as ".au Direct") has been available since the 24th of March, 2022.[8]
Australian territory: not to be confused withCocos Island in Guam. Marketed as a global domain, registration allowed worldwide, local presence not required; the domain is operated by eNIC, aVeriSign company.
A local company in China is required to register a domain name, or for personal registrations a validResident Identity Card. SeeICP license for more information regarding registrations.Hong Kong andMacau also maintain TLDs.
InJapan, "EC" is used as an acronym for "electronic commerce". Because of that, it's used unofficially by companies dedicated to provide online stores like BASE, a company that has two domains related to e-commerce: "base.in" and "official.ec".
EU is an exceptionally reserved ISO 3166-1 code. Restricted to legal and natural persons in European Union member states. Previously unofficially used for sites in theBasque language, but now.eus is in official use.
Must have presence in Gabon or justify any other direct or indirect link with Gabon. Geographical names and names associated with public/government entities prohibited.
Was previously used as a free domain service to the public.
Available for registration for residents of Georgia (unlimited) or for foreign companies via representation of any local legal person (one domain name per registrant).[28]
Restricted to Indonesian companies (co.id), organisations (or.id), academic (ac.id &sch.id) and citizens (biz.id,my.id &web.id). Second-level domains are becoming available now and opened to general registration on 17 August 2014.[32]
In 2002, registration was expanded to include persons or businesses with a "real and substantive" connection with the island ofIreland (includingNorthern Ireland).[33][34]
Used unofficially by technology companies, startups, browser games, and web applications as IO can be an acronym for "input/output" that is useful fordomain hacks.
Restricted to companies, organizations, or government entities based in North Korea. Despite this, few domains are actually registered because ofinternet censorship in North Korea.
Also unofficially used by entities onLong Island,New York or people with the last nameLi. InRussian,li can be used to create domain names that mean a verb with a past tense plural endingli .
Businesses and professionals must be registered as an approved type of organization in the Brønnøysund Register Centre. Individual applicants must be of age (18 years) and be registered in Folkeregisteret. All applicants must have a Norwegian postal address.
All.np domains are free to register for individuals and registered businesses but documents are necessary for verification. Foreign businesses must provide proof of local presence in Nepal.[47]
As a part of a marketing campaign,Lionsgate used the TLD for some (now defunct) sites related toThe Hunger Games franchise, presenting it as the "official" country code of the fictional nation ofPanem; notable sites included thecapitol.pn and revolution.pn.
Registrant must have a registered trademark in Saudi Arabia matching the domain name to register or provide company incorporation documents of a company in Saudi Arabia or for personal registrations a copy of valid ID. A letter on the official letterhead of your organization addressed to SaudiNIC requesting the domain name registration is also required. Local administrative contact required. 2LD registrations rolled out in 2011.[57]
Terres australes et antarctiquesfrançaises (French)
Seldom used. Restricted to individuals and companies in theEuropean Union, Switzerland, Norway, Iceland, and Liechtenstein. The domain also sees frequent use for community-run sites related to the video gameTeam Fortress 2.[L]
Registration allowed worldwide, local presence not required. In line withISO 3166-1, IANA's official position is that "TW" is "designated for use to represent Taiwan, Province of China".[69]
TheISO 3166-1 code for the United Kingdom isGB (forGreatBritain).UK is an exceptionally reserved ISO 3166-1 code. However, the creation of the .uk TLD predates theISO 3166-1 list of ccTLDs and is the primary TLD for the United Kingdom.[71]
Registrants must be United States citizens, residents, or organizations, or a foreign entity with a presence in the United States. Formerly commonly used byU.S. State andlocal governments; see also.gov TLD.
The IANA is not in the business of deciding what is and what is not a country. The selection of the ISO 3166 list as a basis for country code top-level domain names was made with the knowledge that ISO has a procedure for determining which entities should be and should not be on that list.
Almost all ISO 3166-1 codes have been assigned and do exist in DNS.However, some of these are effectively unused. In particular, the ccTLDs for the Norwegian dependencyBouvet Island (bv) and the designationSvalbard and Jan Mayen (sj) do exist in DNS, but no subdomains have been assigned, and it isNorid policy to not assign any at present. TwoFrench territories—bl (Saint Barthélemy) andmf (Saint Martin)—still[update] await local assignment by France's government.
The codeeh, although eligible as ccTLD forWestern Sahara, has never been assigned and does not exist inDNS. Only one subdomain is still registered ingb[83] (ISO 3166-1 for theUnited Kingdom), and no new registrations are being accepted for it. Sites in the United Kingdom generally useuk (see below).
The former.um ccTLD for theU.S. Minor Outlying Islands was removed in April 2008. Under RFC 1591 rules,.um is eligible as a ccTLD on request by the relevant governmental agency and local Internet user community.
Several ASCII ccTLDs are in use that are not ISO 3166-1 two-letter codes. Some of these codes were specified in older versions of the ISO list.
uk (United Kingdom): The ISO 3166-1 code for the United Kingdom is GB (Great Britain). However, theJANET network had already selecteduk as a top-level identifier for its pre-existingName Registration Scheme, and this was incorporated into the DNS root.gb was assigned with the intention of a transition, but this never occurred and the use ofuk is now entrenched.[84]
su This obsolete ISO 3166 code for theSoviet Union was assigned when the Soviet Union still existed; moreover, newsu registrations are accepted.
ac (Ascension Island): This code is a vestige ofIANA's decision in 1996 to allow the use of codes reserved in theISO 3166-1 alpha-2 reserve list for use by theUniversal Postal Union. The decision was later reversed, with Ascension Island now the sole outlier. (Three other ccTLDs,gg (Guernsey),im (Isle of Man) andje (Jersey) also fell under this category from 1996 until they received corresponding ISO 3166 codes in March 2006.)
eu (European Union): On September 25, 2000,ICANN decided to allow the use of any two-letter code in theISO 3166-1 reserve list that is reserved for all purposes. Only EU meets this criterion. Following a decision by the EU's Council of Telecommunications Ministers in March 2002, progress was slow, but aregistry (namedEURid) was chosen by theEuropean Commission, and criteria for allocation set: ICANN approvedeu as a ccTLD, and it opened for registration on 7 December 2005 for the holders of prior rights. Since 7 April 2006, registration is open to all in the European Economic Area.
ccTLDs may be removed if that country ceases to exist. There are three ccTLDs that have been deleted after the corresponding 2-letter code was withdrawn from ISO 3166-1:cs (forCzechoslovakia),zr (forZaire) andtp (forEast Timor). There may be a significant delay between withdrawal from ISO 3166-1 and deletion from the DNS; for example, ZR ceased to be an ISO 3166-1 code in 1997, but thezr ccTLD was not deleted until 2001. Other ccTLDs corresponding to obsolete ISO 3166-1 codes have not yet been deleted. In some cases they may never be deleted due to the amount of disruption this would cause for a heavily used ccTLD. In particular, the Soviet Union's ccTLDsu remains in use more than twenty years after SU was removed from ISO 3166-1.
The temporary reassignment of country codecs (Serbia and Montenegro) until its split intors andme (Serbia andMontenegro, respectively) led to some controversies[85][86] about the stability of ISO 3166-1 country codes, resulting in a second edition of ISO 3166-1 in 2007 with a guarantee that retired codes will not be reassigned for at least 50 years, and the replacement of RFC 3066 by RFC 4646 for country codes used inlanguage tags in 2006.
The previous ISO 3166-1 code forYugoslavia, YU, was removed by ISO on 23 July 2003, but theyu ccTLD remained in operation. Finally, after a two-year transition to Serbianrs and Montenegrinme, the .yu domain was phased out in March 2010.
Australia was originally assigned theoz country code, which was later changed toau with the.oz domains moved to.oz.au.
ICANN started to accept applications for IDN ccTLDs in November 2009,[87] and installed the first set into the Domain Names System in May 2010. The first set was a group of Arabic names for the countries of Egypt, Saudi Arabia, and the United Arab Emirates. By May 2010, 21 countries had submitted applications to ICANN, representing 11 languages.[88]
ICANN requires all potential international TLDs to use at least one letter that does not resemble a Latin letter, or have at least three letters, in an effort to avoidIDN homograph attacks. Nor shall the international domain name look like another domain name, even if they have different alphabets. Between Cyrillic and Greek alphabets, for example, this could happen.[citation needed]
Generic Country Code Top-Level Domain orgccTLD refers to those TLDs which are technically "non-restricted ccTLDs" but used like traditional generic TLDs (gTLDs) rather than "country"-targeted ones.[89][90][91] Most of the gccTLDs are primarily used asdomain hacks:
Lenient registration restrictions on certain ccTLDs have resulted in variousdomain hacks. Domain names such asI.am,tip.it,start.at andgo.to form well-known English phrases, whereas others combine thesecond-level domain and ccTLD to form one word or one title, creating domains such asblo.gs ofSouth Georgia and the South Sandwich Islands (gs),youtu.be ofBelgium (be),del.icio.us of theUnited States (us), andcr.yp.to ofTonga (to). The.co domain of Colombia has been cited since 2010 as a potential competitor to generic TLDs for commercial use, because it may be an abbreviation forcompany.[92]
Some ccTLDs may also be used fortyposquatting. The domaincm ofCameroon has generated interest due to the possibility that people might miss typing the lettero for sites in thecom.[93]
Some of the world's smallest countries and non-sovereign or colonial entities with their own country codes have opened their TLDs for worldwide commercial use, some of them free like.tk.
^Morishita, Yasuhiro Orange (2 September 2003).".JP technical update"(PDF).jprs.jp. RIPE 46 General Meeting. Japan Registry Service, Co., Ltd. (JPRS).Archived(PDF) from the original on 11 October 2011. Retrieved2 April 2017.
