A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country (a sovereign state or a dependent territory).

All ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs. Creation and delegation of ccTLDs is performed by the Internet Assigned Numbers Authority (IANA)as described in RFC 1591, corresponding to ISO 3166-1 alpha-2 country codes with few exceptions explained below.

Delegation and management

The IANA (currently contracted to ICANN) is responsible for determining an appropriate trustee for each ccTLD. Administration and control is then delegated to that trustee, which is responsible for the policies and operation of the domain. The current delegation can be determined from IANA's list of ccTLDs. Individual ccTLDs may have varying requirements and fees for registering subdomains. There may be a local presence requirement (for instance, citizenship or other connection to the ccTLD), as for example the Canadian (ca) and German (de) domains, or registration may be open.

Relation to ISO 3166-1

Unused ISO 3166-1 codes

Almost all current 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 dependency Bouvet Island (bv) and the designation Svalbard and Jan Mayen (sj) do exist in DNS, but no subdomains have been assigned, and it is Norid policy not to assign any at present. Two French territories, bl (Saint Barthélemy) and mf (Saint Martin), await local assignment by France's government.

The code eh, although eligible as ccTLD for Western Sahara, has never been assigned and does not exist in DNS. Only one subdomain is still registered in gb (ISO 3166-1 for United Kingdom) and no new registrations are being accepted for it. Sites in the UK generally use uk (see below).

The former .um ccTLD for the U.S. Minor outlying islands was removed in April 2008. Under RFC 1591 rules .um is eligible as ccTLD on request by the relevant governmental agency and local Internet user community.

ccTLDs not in ISO 3166-1

Six ccTLDs are currently in use despite not being ISO 3166-1 two-letter codes. Some of these codes were in older ISO 3166-1 two-letter codes (now listed in ISO 3166-3).

• uk (United Kingdom): The ISO 3166-1 code for the United Kingdom is GB, however the JANET network had already selected uk as a top-level identifier for its pre-existing Name Registration Scheme, and this was incorporated into the top-level domains. gb was assigned with the intention of a transition, but this never occurred and the use of uk is now entrenched.
• su (the obsolete ISO 3166 code for Soviet Union): Assigned when the Soviet Union was still extant and SU was its assigned ISO 3166 code. The su managers stated in 2001 they will commence accepting new su registrations, but it is unclear whether this action is compatible with ICANN policy.
• ac (Ascension Island): This code is a vestige of IANA's decision in 1996 to allow the use of codes reserved in the ISO 3166-1 alpha-2 reserve list for use by the Universal Postal Union. The decision was later reversed, with Ascension Island now the sole outlier. (Three other ccTLDs, gg (Guernsey), im (Isle of Man) and je (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 in violation of RFC 1591 to allow the use of any two-letter code in the ISO 3166-1 reserve list that is reserved for all purposes. Only EU currently meets this criterion. Following a decision by the EU's Council of Telecommunications Ministers in March 2002, progress was slow, but a registry (named EURid) was chosen by the European Commission, and criteria for allocation set: ICANN approved eu 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.
• tp (the previous ISO 3166-1 code for East Timor): To be phased out in favour of tl during 2005.
• yu (the previous ISO 3166-1 code for Yugoslavia): To be phased out in favour of rs and me before the end of 2009.

Historical ccTLDs

There are two ccTLDs that have been deleted after the corresponding 2-letter code was withdrawn from ISO 3166-1: cs (for Czechoslovakia) and zr (for Zaire). 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 the zr ccTLD was not deleted until 2001. Other ccTLDs corresponding to obsolete ISO 3166-1 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 ccTLD su remains in use more than a decade after SU was removed from ISO 3166-1.

The historical country codes dd for the German Democratic Republic and yd for South Yemen were eligible for a ccTLD, but not allocated; see also de and ye.

The temporary reassignment of country code CS to Serbia and Montenegro until the split into rs (Serbia) and me (Montenegro), led to some controversies with respect to 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 in language tags in 2006.

Australia was originally assigned the oz country code, which was later changed to au with the .oz domains moved to .oz.au.

Internationalized ccTLDs

In December 2006, ICANN established of an internationalized top-level domain name working group within the Country Code Names Supporting Organisation (ccNSO) in December 2006. They resolved in June 2007 inter alia to proceed and asked the IDNC Working Group to prepare a proposal, which the group delivered in June 2008, "to recommend mechanisms to introduce a limited number of non-contentious IDN ccTLDs, associated with the ISO 3166-1 two-letter codes in a short time frame to meet near term demand." The group proposed a methodology using ICANN's Fast Track Process based on the ICANN charter to work with the Internet Assigned Numbers Authority (IANA): 1) Identify technical basis of the TLD strings and country code specific processes, select IDN ccTLD personnel and authorities, and prepare documentation; 2) Perform ICANN due diligence process for technical proposal and publish method; 3) Enter delegation process within established IANA procedures.

Starting November 16, 2009, nations and territories may apply for IDN ccTLDs, which may be expected to be operational in mid-2010. Non-Latin alphabet scripts are used by more than half of the world's 1.6 billion Internet users. ICANN expects that Arabic, Chinese, and Russian domains are likely to be the first implementations.

Unconventional usage

Lenient registration restrictions on certain ccTLDs have resulted in domain names like I.am, tip.it, start.at and go.to. Other variations of ccTLD usage have been called domain hacks, where the second-level domain and ccTLD are used together to form one word or one title. This has resulted in domains like blo.gs of South Georgia and the South Sandwich Islands (gs), del.icio.us of United States of America (us), and cr.yp.to of Tonga (to).

Another form of unconventional ccTLD use results from speculation over typographical errors. The .co domain of Colombia has generated interest ever since it was realized that people might miss typing the "m" for sites in the .com domain, or similarly reach the domain .cm for Cameroon due to a missed "o".

Commercial and vanity use

A number of the world's smallest countries have licensed their TLDs for worldwide commercial use. For example, Tuvalu and the Federated States of Micronesia, small island-states in the Pacific, have partnered with VeriSign and FSM Telecommunications respectively, to sell domain names using the .tv and .fm TLDs to television and radio stations.

Vanity ccTLDs are TLDs which are used for various purposes outside their home countries, because of their name.For example,

• .ac is a ccTLD for Ascension Island, but is sometimes used in Sweden, as "AC" is the abbreviation of the county of Västerbotten.
• .ad is a ccTLD for Andorra, but has recently been increasingly used by advertising agencies or classified advertising.
• .ag is a ccTLD for Antigua and Barbuda and is sometimes used for agricultural sites. In Germany, AG (short for Aktiengesellschaft) is appended to the name of a stock-based company, similar to Inc. in USA.
• .am is a ccTLD for Armenia, but is often used for AM radio stations, or for domain hacks (such as .i.am).
• .as is a ccTLD for American Samoa. In Denmark and Norway, AS is appended to the name of a stock-based company, similar to Inc. in USA. In Czech Republic, the joint stock corporation a.s. abbreviation stands for Akciová společnost.
• .at is a ccTLD for Austria but is used for English words ending in eat (e.at).
• .be is a ccTLD for Belgium, but is sometimes used for the literal term "be" and the Swiss Canton of Bern.
• .by is a ccTLD for Belarus, but is sometimes used in Germany, as "BY" is the official abbreviation of the state Bayern.
• .cc is a ccTLD for Cocos Islands but is used for a wide variety of sites such as community colleges, especially before such institutions were allowed to use .edu.
• .cd is a ccTLD for Democratic Republic of Congo but is used for CD merchants and file sharing sites.
• .ck is a ccTLD for Cook Islands was notably abused in Chris Morris's Nathan Barley by preceding it with ".co" in order to spell out the word cock (.co.ck as in trashbat.co.ck).
• .dj is a ccTLD for Djibouti but is used for CD merchants and disc jockeys.
• .fm is a ccTLD for the Federated States of Micronesia but it is often used for FM radio stations (and even non-FM stations, such as internet radio stations).
• .gg is a ccTLD for Guernsey but it is often used by the gaming and gambling industry, particularly in relation to horse racing and online poker.
• .im is a ccTLD for the Isle of Man but is often used by instant messaging programs and services.
• .in is a ccTLD for India but is widely used in the internet industry.
• .it is a ccTLD for Italy but is used in domain hacks (e.g. .has.it).
• .je is a ccTLD for Jersey but is often used as a diminutive in Dutch (e.g. "huis.je"), as "you" ("zoek.je" = "search you!"), or as "I" in French (e.g. "moi.je")
• .la is a ccTLD for Laos but is marketed as the TLD for Los Angeles.
• .li is a ccTLD for Liechtenstein but is marketed as the TLD for Long Island.
• .lv is a ccTLD for Latvia but is also used to abbreviate Las Vegas or less frequently, love.
• .ly is a ccTLD for Libya but is also used for words ending with suffix "ly".
• .md is a ccTLD for Moldova, but is marketed to the medical industry (as in "medical domain" or "medical doctor").
• .me is a ccTLD for Montenegro, and is recently opened to individuals.
• .mn is a ccTLD for Mongolia, but is used to abbreviate Minnesota.
• .ms is a ccTLD for Montserrat, but is also used by Microsoft for such projects as popfly.ms.
• .mu is a ccTLD for Mauritius, but is used within the music industry.
• .ni is a ccTLD for Nicaragua, but is occasionally adopted by companies from Northern Ireland, particularly to distinguish from the more usual .uk within all parts of the United Kingdom
• .nu is a ccTLD for Niue but marketed as resembling "new" in English and "now" in Scandinavian/Dutch. Also meaning "nude" in French/Portuguese.
• .pr is a ccTLD for Puerto Rico, but can be used in the meaning of "Public Relations"
• .sc is a ccTLD for Seychelles but is often used as .Source
• .sh is a ccTLD for Saint Helena, but is also sometimes used for entities connected to the German Bundesland of Schleswig-Holstein or the Swiss Canton of Schaffhausen.
• .si is a ccTLD for Slovenia, but is also used by Hispanic sites as "yes" ("sí"). Mexican mayor candidate Jorge Arana, for example, had his web site registered as http://www.jorgearana.si (i.e. "Jorge Arana, sí", meaning Jorge Arana, yes").
• .sr is a ccTLD for Suriname but is marketed as being for "seniors".
• .st is a ccTLD for São Tomé and Príncipe but is being marketed worldwide as an abbreviation for various things including "street".
• .tk is a ccTLD for Tokelau but is bought by someone and given away at dot.tk page
• .tm is a ccTLD for Turkmenistan but it can be used as "Trade Mark"
• .to is a ccTLD for Tonga but is often used as the English word "to", like "go.to"; also is marketed as the TLD for Toronto.
• .tv is a ccTLD for Tuvalu but it is used for the television ("TV") / entertainment industry purposes.
• .vg is a ccTLD for British Virgin Islands but is sometimes used to abbreviate Video games
• .vu is a ccTLD for Vanuatu but means "seen" in French as well as an abbreviation for the English language word "view".
• .ws is a ccTLD for Samoa (earlier Western Samoa), but is marketed as .Website

List of ccTLDs

* Foreign registration permitted ===A=== * [[.ac]] – [[Ascension Island]]* * [[.ad]] – [[Andorra]] * [[.ae]] – [[United Arab Emirates]] * [[.af]] – [[Afghanistan]] * [[.ag]] – [[Antigua and Barbuda]]* * [[.ai]] – [[Anguilla]] * [[.al]] – [[Albania]] * [[.am]] – [[Armenia]]* * [[.an]] – [[Netherlands Antilles]] * [[.ao]] – [[Angola]] * [[.aq]] – [[Antarctica]] * [[.ar]] – [[Argentina]] * [[.as]] – [[American Samoa]]* * [[.at]] – [[Austria]]* * [[.au]] – [[Australia]] * [[.aw]] – [[Aruba]] * [[.ax]] – [[Åland Islands]] * [[.az]] – [[Azerbaijan]] ===B=== * [[.ba]] – [[Bosnia and Herzegovina]] * [[.bb]] – [[Barbados]] * [[.bd]] – [[Bangladesh]] * [[.be]] – [[Belgium]]* * [[.bf]] – [[Burkina Faso]] * [[.bg]] – [[Bulgaria]] * [[.bh]] – [[Bahrain]] * [[.bi]] – [[Burundi]]* * [[.bj]] – [[Benin]] * [[.bl]] – [[Saint Barthélemy]] * [[.bm]] – [[Bermuda]] * [[.bn]] – [[Brunei]] * [[.bo]] – [[Bolivia]]* * [[.br]] – [[Brazil]]* * [[.bs]] – [[The Bahamas|Bahamas]]* * [[.bt]] – [[Bhutan]] * [[.bv]] – [[Bouvet Island]] ''(not in use; no registrations)'' * [[.bw]] – [[Botswana]] * [[.by]] – [[Belarus]] * [[.bz]] – [[Belize]]* ===C=== * [[.ca]] – [[Canada]] * [[.cc]] – [[Cocos (Keeling) Islands]]* * [[.cd]] – [[Democratic Republic of the Congo]] (''formerly'' .zr – [[Zaire]])* * [[.cf]] – [[Central African Republic]] * [[.cg]] – [[Republic of the Congo]]* * [[.ch]] – [[Switzerland]] (''Confoederatio Helvetica'') * * [[.ci]] – [[Côte d'Ivoire]] (Ivory Coast)* * [[.ck]] – [[Cook Islands]]* * [[.cl]] – [[Chile]] * [[.cm]] – [[Cameroon]] * [[.cn]] – [[People's Republic of China]]* * [[.co]] – [[Colombia]] * [[.cr]] – [[Costa Rica]] * [[.cu]] – [[Cuba]] * [[.cv]] – [[Cape Verde]] * [[.cx]] – [[Christmas Island]]* * [[.cy]] – [[Cyprus]] * [[.cz]] – [[Czech Republic]] ===D=== * [[.de]] – [[Germany]] * [[.dj]] – [[Djibouti]]* * [[.dk]] – [[Denmark]]* * [[.dm]] – [[Dominica]] * [[.do]] – [[Dominican Republic]] * [[.dz]] – [[Algeria]] ===E=== * [[.ec]] – [[Ecuador]]* * [[.ee]] – [[Estonia]] * [[.eg]] – [[Egypt]], applied for .مصر‎ (misr) * [[.eh]] – [[Western Sahara]] ''(not assigned; no DNS)'' * [[.er]] – [[Eritrea]] * [[.es]] – [[Spain]]* * [[.et]] – [[Ethiopia]] * [[.eu]] – [[European Union]] ''(code "exceptionally reserved" by ISO 3166–1)'' ===F=== * [[.fi]] – [[Finland]] * [[.fj]] – [[Fiji]]* * [[.fk]] – [[Falkland Islands]] * [[.fm]] – [[Federated States of Micronesia]]* * [[.fo]] – [[Faroe Islands]] * [[.fr]] – [[France]] ===G=== * [[.ga]] – [[Gabon]] * [[.gb]] – [[United Kingdom]] ''(Reserved domain by IANA; deprecated – see [[.uk]])'' * [[.gd]] – [[Grenada]]* * [[.ge]] – [[Georgia (country)|Georgia]] * [[.gf]] – [[French Guiana]] * [[.gg]] – [[Guernsey]] * [[.gh]] – [[Ghana]] * [[.gi]] – [[Gibraltar]] * [[.gl]] – [[Greenland]]* * [[.gm]] – [[The Gambia|Gambia]] * [[.gn]] – [[Guinea]] * [[.gp]] – [[Guadeloupe]] * [[.gq]] – [[Equatorial Guinea]] * [[.gr]] – [[Greece]]* * [[.gs]] – [[South Georgia and the South Sandwich Islands]]* * [[.gt]] – [[Guatemala]] * [[.gu]] – [[Guam]] * [[.gw]] – [[Guinea-Bissau]] * [[.gy]] – [[Guyana]] ===H=== * [[.hk]] – [[Hong Kong]]* * [[.hm]] – [[Heard Island and McDonald Islands]]* * [[.hn]] – [[Honduras]]* * [[.hr]] – [[Croatia]] * [[.ht]] – [[Haiti]] * [[.hu]] – [[Hungary]]* ===I=== * [[.id]] – [[Indonesia]] * [[.ie]] – [[Ireland]] * [[.il]] – [[Israel]]* * [[.im]] – [[Isle of Man]]* * [[.in]] – [[India]]* * [[.io]] – [[British Indian Ocean Territory]]* * [[.iq]] – [[Iraq]] * [[.ir]] – [[Iran]]* * [[.is]] – [[Iceland]]* * [[.it]] – [[Italy]] ===J=== * [[.je]] – [[Jersey]] * [[.jm]] – [[Jamaica]] * [[.jo]] – [[Jordan]] * [[.jp]] – [[Japan]] ===K=== * [[.ke]] – [[Kenya]] * [[.kg]] – [[Kyrgyzstan]] * [[.kh]] – [[Cambodia]] * [[.ki]] – [[Kiribati]] * [[.km]] – [[Comoros]] * [[.kn]] – [[Saint Kitts and Nevis]] * [[.kp]] – [[North Korea]] * [[.kr]] – [[South Korea]] * [[.kw]] – [[Kuwait]] * [[.ky]] – [[Cayman Islands]] * [[.kz]] – [[Kazakhstan]]* ===L=== * [[.la]] – [[Laos]]* * [[.lb]] – [[Lebanon]] * [[.lc]] – [[Saint Lucia]] * [[.li]] – [[Liechtenstein]]* * [[.lk]] – [[Sri Lanka]] * [[.lr]] – [[Liberia]] * [[.ls]] – [[Lesotho]]* * [[.lt]] – [[Lithuania]] * [[.lu]] – [[Luxembourg]] * [[.lv]] – [[Latvia]]* * [[.ly]] – [[Libya]]* ===M=== * [[.ma]] – [[Morocco]] * [[.mc]] – [[Monaco]] * [[.md]] – [[Moldova]]* * [[.me]] – [[Montenegro]]* * [[.mg]] – [[Madagascar]] * [[.mh]] – [[Marshall Islands]] * [[.mk]] – [[Republic of Macedonia]] * [[.ml]] – [[Mali]] * [[.mm]] – [[Myanmar]] * [[.mn]] – [[Mongolia]]* * [[.mo]] – [[Macau]] * [[.mp]] – [[Northern Mariana Islands]]* * [[.mq]] – [[Martinique]] * [[.mr]] – [[Mauritania]] * [[.ms]] – [[Montserrat]]* * [[.mt]] – [[Malta]] * [[.mu]] – [[Mauritius]]* * [[.mv]] – [[Maldives]] * [[.mw]] – [[Malawi]]* * [[.mx]] – [[Mexico]]* * [[.my]] – [[Malaysia]] * [[.mz]] – [[Mozambique]] ===N=== * [[.na]] – [[Namibia]]* * [[.nc]] – [[New Caledonia]] * [[.ne]] – [[Niger]] * [[.nf]] – [[Norfolk Island]]* * [[.ng]] – [[Nigeria]] * [[.ni]] – [[Nicaragua]] * [[.nl]] – [[Netherlands]]* * [[.no]] – [[Norway]] * [[.np]] – [[Nepal]] * [[.nr]] – [[Nauru]]* * [[.nu]] – [[Niue]]* * [[.nz]] – [[New Zealand]]* ===O=== * [[.om]] – [[Oman]] ===P=== * [[.pa]] – [[Panama]] * [[.pe]] – [[Peru]] * [[.pf]] – [[French Polynesia]] * [[.pg]] – [[Papua New Guinea]] * [[.ph]] – [[Philippines]]* * [[.pk]] – [[Pakistan]]* * [[.pl]] – [[Poland]]* * [[.pm]] – [[Saint Pierre and Miquelon]] * [[.pn]] – [[Pitcairn Islands]]* * [[.pr]] – [[Puerto Rico]]* * [[.ps]] – [[State of Palestine|Palestine]]* * [[.pt]] – [[Portugal]]* * [[.pw]] – [[Palau]] * [[.py]] – [[Paraguay]] ===Q=== * [[.qa]] – [[Qatar]] ===R=== * [[.re]] – [[Réunion]] * [[.ro]] – [[Romania]]* * [[.rs]] – [[Serbia]]* * [[.ru]] – [[Russia]]* * [[.rw]] – [[Rwanda]] ===S=== * [[.sa]] – [[Saudi Arabia]] * [[.sb]] – [[Solomon Islands]]* * [[.sc]] – [[Seychelles]]* * [[.sd]] – [[Sudan]] * [[.se]] – [[Sweden]]* * [[.sg]] – [[Singapore]] * [[.sh]] – [[Saint Helena]]* * [[.si]] – [[Slovenia]] * [[.sj]] – [[Svalbard and Jan Mayen]] islands ''(not in use; no registrations)'' * [[.sk]] – [[Slovakia]] * [[.sl]] – [[Sierra Leone]] * [[.sm]] – [[San Marino]]* * [[.sn]] – [[Senegal]] * [[.so]] – [[Somalia]] * [[.sr]] – [[Suriname]]* * [[.st]] – [[São Tomé and Príncipe]]* * [[.su]] – [[Soviet Union]] ''(deprecated; being phased out; code "transitionally reserved" by ISO 3166–1)'' * [[.sv]] – [[El Salvador]] * [[.sy]] – [[Syria]]* * [[.sz]] – [[Swaziland]]* ===T=== * [[.tc]] – [[Turks and Caicos Islands]]* * [[.td]] – [[Chad]] * [[.tf]] – [[French Southern and Antarctic Lands]] * [[.tg]] – [[Togo]]* * [[.th]] – [[Thailand]]* * [[.tj]] – [[Tajikistan]]* * [[.tk]] – [[Tokelau]]* * [[.tl]] – [[East Timor]] ''(formerly .tp)''* * [[.tm]] – [[Turkmenistan]]* * [[.tn]] – [[Tunisia]] * [[.to]] – [[Tonga]]* * [[.tp]] – [[East Timor]] ''(deprecated – use .tl; code "transitionally reserved" by ISO 3166–1)'' * [[.tr]] – [[Turkey]] * [[.tt]] – [[Trinidad and Tobago]]* * [[.tv]] – [[Tuvalu]]* * [[.tw]] – [[Taiwan]]* * [[.tz]] – [[Tanzania]] ===U=== * [[.ua]] – [[Ukraine]] * [[.ug]] – [[Uganda]]* * [[.uk]] – [[United Kingdom]] ''(code "exceptionally reserved" by ISO 3166–1) (see also [[.gb]])'' * [[.um]] – [[US Minor Outlying Islands]] ''(code terminated)'' * [[.us]] – [[United States]]* * [[.uy]] – [[Uruguay]] * [[.uz]] – [[Uzbekistan]] ===V=== * [[.va]] – [[Vatican City]] * [[.vc]] – [[Saint Vincent and the Grenadines]]* * [[.ve]] – [[Venezuela]] * [[.vg]] – [[British Virgin Islands]]* * [[.vi]] – [[United States Virgin Islands]] * [[.vn]] – [[Vietnam]] * [[.vu]] – [[Vanuatu]]* ===W=== * [[.wf]] – [[Wallis and Futuna]] * [[.ws]] – [[Samoa]]* ''(formerly Western Samoa)'' ===Y=== * [[.ye]] – [[Yemen]] * [[.yt]] – [[Mayotte]] * [[.yu]] – [[Yugoslavia]] ===Z=== * [[.za]] – [[South Africa]]* * [[.zm]] – [[Zambia]] * [[.zw]] – [[Zimbabwe]] * Foreign registration permitted

References

External links

• IANA's list of ccTLDs – official site
• World Intellectual Property Organization (WIPO) Domain name dispute resolution]
• World-Wide Alliance of Top Level Domain-names
• Norid: Domain name registries around the world
• ccTLD and TLD analysis of several Zone files
• The ICANN Country Code Names Supporting Organisation (ccNSO)