Second-level domain
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.
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:
- .co.at intended for commercial enterprises
- .or.at intended for organizations.[1]
The second-level domain
- .priv.at is restricted to Austrian citizens only, while
- .ac.at and .gv.at are reserved for educational institutions and governmental bodies respectively.[2][3]
Brazil
France
In France, there are various second-level domains available for certain sectors, including
- .avocat.fr for attorneys,
- .aeroport.fr for airports and
- .veterinaire.fr for vets.[4]
Hungary
New Zealand
Nigeria
- .com.ng
- .gov.ng
Pakistan
India
Israel
Japan
Russia
South Africa
South Korea
Spain
Sri Lanka
Thailand
Trinidad and Tobago
- co.tt
- com.tt
- org.tt
- net.tt
- travel.tt
- museum.tt
- aero.tt
- tel.tt
- name.tt
- charity.tt
- mil.tt
- edu.tt
- gov.tt
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:
- .gov.ua – available for government agencies.
- .com.ua – for commercial use.
- .in.ua – for commercial use.
- .org.ua – intended for non-profit organizations.
- .net.ua – intended for Internet providers.
- .edu.ua – for academic institutions.
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 ccTLD was replaced by {{Not a typo|.rs} nd .me (for Monteneg Second-level domains under .yu included: – for academic institutions, .co.yu} terprises; .org.yu for organizatio .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
Legal issues
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 , as well. For example, second-level domains under .tobacco .diet.health can be easily misuse e are a potential threat to Internet users.[18]
See also
- Single-letter second-level domains
- Domain Name System
- Top-level domain
- Country code top-level domain
- Subdomain
- Private sub-domain registry
- Public Suffix List
- .ac (second-level domain)
- .edu (second-level domain)
References
- ↑ "Useful information about .or.at domains". http://www.easyname.com/en/or.at-domain.
- ↑ "Domain registration". https://www.nic.at/en/print/uebernic/company_details_imprint/internet_foundation_austria_ipa/principles_and_grants/.
- ↑ "Principles and Grants". https://www.nic.at/en/print/uebernic/company_details_imprint/internet_foundation_austria_ipa/principles_and_grants/.
- ↑ "Sector-based .fr domains". http://www.afnic.fr/en/products-and-services/the-fr-tld/sector-based-fr-domains-4.html.
- ↑ "Overview". https://www.nic.tr/index.php?PHPSESSID=14145415321448218799326880&USRACTN=STATICHTML&PAGE=about_corpident.
- ↑ "Who could register which domain name?". https://www.nic.tr/index.php#102.
- ↑ "Can an individual or a company in abroad register a ".tr" domain name?". https://www.nic.tr/index.php#102.
- ↑ "Who could register which domain name?". https://www.nic.tr/index.php#102.
- ↑ "the australian second level domain name system". http://www.bladesplace.id.au/australian-domains.html.
- ↑ "General Registration Rules, Version 3.21, February 5, 2015". https://cira.ca/sites/default/files/public/policy/general_registration_rules_version_3.21_february_5_2015.pdf. Retrieved 18 November 2017.
- ↑ "Useful information about .fr domains". http://www.easyname.com/en/fr-domain.
- ↑ "ICANN-Registrar: French Domains with Accents". http://www.domainregistry.de/fr-domain.html.
- ↑ "Commercial, national & international character with a .co.nl domain name". http://domain.co.nl/en.
- ↑ ".Co.NL WhoIS". https://whois.co.nl.
- ↑ ".RS - Republic of Serbia .ME - Republic of Montenegro (Former parts of Yugoslavia) Formerly .YU and .CS Country Codes.". http://tldv.com/Dot-yu-Yugoslavia.htm.
- ↑ "Delegated strings". http://newgtlds.icann.org/en/program-status/delegated-strings.
- ↑ 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.
- ↑ 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. PMID 24598602.
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