.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. 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.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.Hungary
New Zealand
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.ttTurkey
In Turkey, domain registrations, including the registration of second-level domains is administrated bUkraine
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: originally intended for conferences; for the Australian Academic and Research networks; ' for general information, ' and ' for the X.400 mail systems.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 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).France
Historic second-level domains for France included: ''.tm.fr'' (for brands), .''com.fr'' (for commercial use) and ''{{Not a typo, .asso.fr.''The Netherlands
Historic second-level domains for the Netherlands included: .''co.nl'' (for commercial use)Yugoslavia
In 2006 the {{Not a typo, .yu ccTLD was replaced by ''{{Not a typo, .rs'' (for Serbia) and ''{{Not a typo, .me'' (for Montenegro). Second-level domains under {{Not a typo, .yu included: ''{{Not a typo, .ac.yu'' – for academic institutions, ''{{Not a typo, .co.yu'' for commercial enterprises; ''{{Not a typo, .org.yu'' for organizations and ''{{Not a typo, .cg.yu'' for residents of Montenegro. Only legal entities were allowed to register names under ''{{Not a typo, .yu'' and its second-level domains.Tuvalu
Historic second-level domains for Tuvalu includedLegal issues
As a result of ICANN's generic top-level domain (gTLD) expansion, the risk of domain squatting has increased significantly. For example, based on current regulations, the registration of the gTLDs ''{{Not a typo, .olympics'' or ''{{Not a typo, .redcross'' is not allowed; however, the registration of sites such as ''{{Not a typo, olympics.example'' or ''{{Not a typo, redcross.example'' is not controlled. Experts say {{who, date=May 2021 that further restrictions are needed for second-level domains under the new gTLD ''{{Not a typo, .health'', as well. For example, second-level domains under ''{{Not a typo, .tobacco.health'' or ''{{Not a typo, .diet.health'' can be easily misused by companies and therefore are a potential threat to Internet users.{{cite journal, last1=Mackey, first1=TK, last2=Liang, first2=BA, last3=Kohler, first3=JC, last4=Attaran, first4=A, title=Health Domains for Sale: The Need for Global Health Internet Governance, journal=J Med Internet Res, date=5 March 2014, volume=16, issue=3, doi=10.2196/jmir.3276, pmid=24598602, url=http://www.jmir.org/2014/3/e62/, access-date=2014-10-29, pmc=3961808, page=e62See also
*References
{{Reflist {{course assignment , course = Education Program:University College London/MSIN1003 Information World (Autumn 2014) , term = 2014 Q3 {{DEFAULTSORT:Second-Level Domain Domain Name System