Second-level domain

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In the Domain Name System (DNS) hierarchy, a second-level domain (SLD or 2LD) is a domain that is directly below a top-level domain (TLD). For example, in example.com, example is the second-level domain of the .com TLD.

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Second-level domains commonly refer to the organization that registered the domain name with a domain name registrar. Some domain name registries introduce a second-level hierarchy to a TLD that indicates the type of entity intended to register an SLD under it. For example, in the .uk namespace a college or other academic institution would register under the .ac.uk ccSLD, while companies would register under .co.uk. Strictly speaking, domains like .ac.uk and .co.uk are second level domain themselves, since they are right below a TLD. A list of the official TLDs can be found at icann.org and iana.org. An ordinal-free term to denote domains under which people can register their own domain name is public suffix domain (PSD).

Country-code second-level domains

Algeria

Australia

Austria

In Austria there are two second-level domains available for the public:

The second-level domain

Brazil

France

In France, there are various second-level domains available for certain sectors, including

Hungary

New Zealand

Nigeria

Pakistan

India

As of 2005, liberalised policies for the .in domain allow unlimited second-level registrations under .in. Unlimited registrations under the previously structured existing zones are also allowed:

Zones reserved for use by qualified institutions in India:

Before the introduction of liberalised registration policies for the .in domain, only 7000 names had been registered between 1992 and 2004. As of March 2010, the number had increased to over 610,000 domain names with 60% of registrations coming from India and the rest from overseas. By October 2011, the number had surpassed 1 million domain names. As of March 2016, the number has more than doubled to over 2 million domain names.

Israel

Japan

Russia

South Africa

South Korea

Spain

Sri Lanka

Registrations are taken at the second level and also at the third level beneath various categorized second level names. A second-level registration automatically blocks the name from registration by anybody else under any of the third-level names.

Thailand

Trinidad and Tobago

Turkey

In Turkey, domain registrations, including the registration of second-level domains is administrated by nic.tr. [5] There 17 active second-level domains under the .tr TLD. [6] The registration of domains is restricted to Turkish individuals and businesses, or foreign companies with a business activity in Turkey. [7] Second-level domains include .com.tr for commercial ventures, .edu.tr for academic institutions and .name.tr for personal use. [8]

Ukraine

Ukraine second-level domains include:

There are also numerous geographic names.

United Kingdom

United States

A two-letter second-level domain is formally reserved for each U.S. state, federal territory, and the District of Columbia.

Zambia

Historic second-level domains

There are several second-level domains which are no longer available.

Australia

Second-level domains under .au which are no longer available include: .conf.au originally intended for conferences; .gw.au for the Australian Academic and Research networks; info.au for general information, .otc.au and .telememo.au for the X.400 mail systems. [9]

Canada

Prior to 12 Oct 2010 there were second level domain based on province: .ab.ca — Alberta, .bc.ca — British Columbia, .mb.ca — Manitoba, .nb.ca — New Brunswick, .nf.ca — Newfoundland, .nl.ca — Newfoundland and Labrador, .ns.ca — Nova Scotia, .nt.ca — Northwest Territories, .nu.ca — Nunavut, .on.ca — Ontario, .pe.ca — Prince Edward Island, .qc.ca — Quebec, .sk.ca — Saskatchewan, .yk.ca — Yukon [ citation needed ]

Since 2010, some have been replaced (for example, alberta.ca) while others have remained under the provincial two letter SLD (e.g., Calgary Board of Education www.cbe.ab.ca) and others were moved to more traditional subdomains (www.transportation.alberta.ca). [10]

France

Historic second-level domains for France included: .tm.fr (for brands), .com.fr (for commercial use) and .asso.fr. [11] [12]

The Netherlands

Historic second-level domains for the Netherlands included: .co.nl (for commercial use) [13] [14]

Yugoslavia

In 2006 the .yu ccTLD was replaced by .rs (for Serbia) and .me (for Montenegro). Second-level domains under .yu included: .ac.yu – for academic institutions, .co.yu for commercial enterprises; .org.yu for organizations and .cg.yu for residents of Montenegro. Only legal entities were allowed to register names under .yu and its second-level domains. [15]

Tuvalu

Historic second-level domains for Tuvalu included: co.tv

As a result of ICANN's generic top-level domain (gTLD) expansion, [16] the risk of domain squatting has increased significantly. For example, based on current regulations, the registration of the gTLDs .olympics or .redcross is not allowed; however, the registration of sites such as olympics.example or redcross.example is not controlled. [17] Experts say [ who? ] that further restrictions are needed for second-level domains under the new gTLD .health, as well. For example, second-level domains under .tobacco.health or .diet.health can be easily misused by companies and therefore are a potential threat to Internet users. [18]

See also

Related Research Articles

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.

<span class="mw-page-title-main">Domain name</span> Identification string in the Internet

In the Internet, a domain name is a string that identifies a realm of administrative autonomy, authority or control. Domain names are often used to identify services provided through the Internet, such as websites, email services and more. Domain names are used in various networking contexts and for application-specific naming and addressing purposes. In general, a domain name identifies a network domain or an Internet Protocol (IP) resource, such as a personal computer used to access the Internet, or a server computer.

A domain name registry is a database of all domain names and the associated registrant information in the top level domains of the Domain Name System (DNS) of the Internet that enables third party entities to request administrative control of a domain name. Most registries operate on the top-level and second-level of the DNS.

The domain com is a top-level domain (TLD) in the Domain Name System (DNS) of the Internet. Created in the first group of Internet domains at the beginning of 1985, its name is derived from the word commercial, indicating its original intended purpose for subdomains registered by commercial organizations. Later, the domain opened for general purposes.

<span class="mw-page-title-main">.org</span> Generic top-level domain

The domain name .org is a generic top-level domain (gTLD) of the Domain Name System (DNS) used on the Internet. The name is truncated from 'organization'. It was one of the original domains established in 1985, and has been operated by the Public Interest Registry since 2003. The domain was originally "intended as the miscellaneous TLD for organizations that didn't fit anywhere else." It is commonly used by non-profit organizations, open-source projects, and communities, but is an open domain that can be used by anyone. The number of registered domains in .org has increased from fewer than one million in the 1990s, to ten million in 2012, and held steady between ten and eleven million since then.

<span class="mw-page-title-main">.uk</span> Internet country code top-level domain for the United Kingdom

.uk is the Internet country code top-level domain (ccTLD) for the United Kingdom. It was first registered in July 1985, seven months after the original generic top-level domains such as .com and the first country code after .us.

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.

.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.

<span class="mw-page-title-main">.il</span> Internet country code top-level domain for Israel

.il is the Internet country code top-level domain (ccTLD) of Israel, administered by the Israel Internet Association and managed by NIC - ISRAEL, which hosts the DNS root server and manages the Israeli Internet Exchange, that supports IPv4 and IPv6.

The Canadian Internet Registration Authority (CIRA) is the organization that manages the .ca country code top-level domain (ccTLD) for Canada. Its offices are located at 979 Bank Street in Ottawa, Ontario, Canada. CIRA sets the policies and agendas that support Canada's internet community and Canada's involvement in international internet governance. It is a member-driven organization with membership open to all that hold a .ca domain. As of March 2023, there were more than 3.3 million active .ca domains.

<span class="mw-page-title-main">.co</span> Internet country-code top level domain for Colombia

.co is the Internet country code top-level domain (ccTLD) assigned to Colombia.

.zm is the Internet country code top-level domain (ccTLD) for Zambia. Registrants of .zm domains must "have a presence in Zambia".

<span class="mw-page-title-main">.in</span> Internet country code top-level domain for India

.in is the Internet country code top-level domain (ccTLD) for India. It was made available in 1989, four years after original generic top-level domains such as .com, .net and the country code like .us. It is currently administered by the National Internet Exchange of India (NIXI).

<span class="mw-page-title-main">.gr</span> Internet country code top-level domain for Greece

.gr is the country code top-level domain (ccTLD) for Greece. Registrations are processed via accredited registrars and domain names in Greek characters may also be registered.

<span class="mw-page-title-main">.lk</span> Internet country code top-level domain for Sri Lanka

.lk is the Internet country code top-level domain (ccTLD) for Sri Lanka. Foreign companies who do not have a local presence can only reserve their top-level and corresponding open second-level domains. In order to register and use a name they must have a contact address in Sri Lanka.

Single-letter second-level domains are domains in which the second-level domain of the domain name consists of only one letter, such as x.com. In 1993, the Internet Assigned Numbers Authority (IANA) explicitly reserved all single-letter and single-digit second-level domains under the top-level domains com, net, and org, and grandfathered those that had already been assigned. In December 2005, ICANN considered auctioning these domain names.

<span class="mw-page-title-main">.rs</span> Internet country code top-level domain for Serbia

.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.

<span class="mw-page-title-main">.me</span> Internet top level domain for Montenegro

.me is the Internet country code top-level domain (ccTLD) for Montenegro.

<span class="mw-page-title-main">.рф</span> Cyrillic Internet country code top-level domain for the Russian Federation

The domain name .рф is the Cyrillic country code top-level domain for the Russian Federation, in the Domain Name System of the Internet. In the Domain Name System it has the ASCII DNS name xn--p1ai. The domain accepts only Cyrillic subdomain applications, and is the first Cyrillic implementation of the Internationalizing Domain Names in Applications (IDNA) system. The domain became operational on 13 May 2010. As of 2014 it is the most used internationalized country code top-level domain, with around 900,000 domain names.

<span class="mw-page-title-main">ZA Central Registry</span> Non-profit that operates various second-level domains in South Africa

The ZA Central Registry (ZACR), formerly known as UniForum SA, is a non-profit organisation established in 1988 and operates various second-level domains (SLD's) in South Africa. The ZA Central Registry is the administrator of the South African zones such as "co.za" and "web.za". Their offices are based in Midrand, South Africa.

References

  1. ↑ "Useful information about .or.at domains" . Retrieved 29 October 2014.
  2. ↑ "Domain registration" . Retrieved 29 October 2014.
  3. ↑ "Principles and Grants" . Retrieved 29 October 2014.
  4. ↑ "Sector-based .fr domains" . Retrieved 31 October 2014.
  5. ↑ "Overview" . Retrieved 29 October 2014.
  6. ↑ "Who could register which domain name?" . Retrieved 29 October 2014.
  7. ↑ "Can an individual or a company in abroad register a ".tr" domain name?" . Retrieved 29 October 2014.
  8. ↑ "Who could register which domain name?" . Retrieved 29 October 2014.
  9. ↑ "the australian second level domain name system" . Retrieved 31 October 2014.
  10. ↑ "General Registration Rules, Version 3.21, February 5, 2015" (PDF). Archived from the original (PDF) on 2017-12-01. Retrieved 18 November 2017.
  11. ↑ "Useful information about .fr domains" . Retrieved 31 October 2014.
  12. ↑ "ICANN-Registrar: French Domains with Accents" . Retrieved 31 October 2014.
  13. ↑ "Commercial, national & international character with a .co.nl domain name" . Retrieved 25 January 2016.
  14. ↑ ".Co.NL WhoIS" . Retrieved 25 January 2016.
  15. ↑ ".RS - Republic of Serbia .ME - Republic of Montenegro (Former parts of Yugoslavia) Formerly .YU and .CS Country Codes" . Retrieved 31 October 2014.
  16. ↑ "Delegated strings" . Retrieved 29 October 2014.
  17. ↑ Easton, Catherine R. (2012). "ICANN's core principles and the expansion of generic top-level domain names". International Journal of Law and Information Technology. 20 (4): 273–290. doi:10.1093/ijlit/eas013.
  18. ↑ Mackey, TK; Liang, BA; Kohler, JC; Attaran, A (5 March 2014). "Health Domains for Sale: The Need for Global Health Internet Governance". J Med Internet Res. 16 (3): e62. doi: 10.2196/jmir.3276 . PMC   3961808 . PMID   24598602.
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