Second-level domain
In theDomain Name System(DNS) hierarchy, asecond-level domain(SLDor2LD) is a domain that is directly below atop-level domain(TLD). For example, inexample.com,exampleis the second-level domain of the.comTLD.
Second-level domains commonly refer to the organization that registered the domain name with adomain name registrar.Somedomain name registriesintroduce a second-level hierarchy to a TLD that indicates the type of entity intended to register an SLD under it. For example, in the.uknamespace a college or other academic institution would register under the.ac.ukccSLD,while companies would register under.co.uk.Strictly speaking, domains like.ac.ukand.co.ukare 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 ispublic suffix domain(PSD).
Country-code second-level domains[edit]
Algeria[edit]
Australia[edit]
Austria[edit]
In Austria there are two second-level domains available for the public:
- .co.atintended for commercial enterprises
- .or.atintended for organizations.[1]
The second-level domain
- .priv.atis restricted to Austrian citizens only, while
- .ac.atand.gv.atare reserved for educational institutions and governmental bodies respectively.[2][3]
Bangladesh[edit]
- .com.bd,.net.bdand.org.bdis open for registration for all Bangladeshi citizens and companies.
- .edu.bdand.ac.bdis open for all kinds of educational institutions in Bangladesh.
- .info.bdis restricted for personal use.
- .co.bdis open for companies or agencies. But presently not available for registration.
- .gov.bdis restricted to the government entities.
- .mil.bdis restricted for military use.
- .tv.bdis open for broadcasting and media agencies.
Brazil[edit]
France[edit]
In France, there are various second-level domains available for certain sectors, including
- .avocat.frfor attorneys,
- .aeroport.frfor airports and
- .veterinaire.frfor vets.[4]
Hungary[edit]
New Zealand[edit]
Nigeria[edit]
- com.ng– open domain, commercial entities and businesses
- org.ng– semi-open domain, non-commercial organizations
- gov.ng– closed domain, governmental organizations
- edu.ng– closed domain, degree awarding institutions
- net.ng– closed domain, ISP infrastructure
- sch.ng– closed domain, secondary schools
- name.ng– open domain, individuals
- mobi.ng– open domain, suitable for mobile devices
- mil.ng– closed domain (Nigerian military establishments only)
- i.ng– open domain, any purpose
Pakistan[edit]
India[edit]
As of 2005[update],liberalised policies for the.indomain allow unlimited second-level registrations under.in.Unlimited registrations under the previously structured existing zones are also allowed:
- .in(available to anyone; used by companies, individuals, and organisations in India)
- .co.in(intended for banks, registered companies, and trademarks)
- .com.in(available to anyone; used by companies, individuals, and organisations in India)
- .firm.in(intended for shops,partnerships,liaison offices,sole proprietorships)
- .net.in(intended forInternet service providers)
- .org.in(intended fornonprofit organisations)
- .gen.in(intended for general/miscellaneous use)
- .ind.in(intended for individuals)
Zones reserved for use by qualified institutions in India:
- .ernet.in(Older, for both educational and research institutes)
- .ac.in(Academic institutions)
Before the introduction of liberalised registration policies for the.indomain, only 7000 names had been registered between 1992 and 2004. As of March 2010[update],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[update],the number has more than doubled to over 2 million domain names.
Israel[edit]
Japan[edit]
Russia[edit]
South Africa[edit]
South Korea[edit]
Spain[edit]
Sri Lanka[edit]
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.
- .com.lk:Commercial entities
- .org.lk:Noncommercial organizations
- .edu.lk:Educational sites
- .ngo.lk:Non-governmental organizations
- .soc.lk:Registered societies
- .web.lk:Web sites
- .ltd.lk:Limited liability companies
- .assn.lk:Associations
- .grp.lk:Groups of companies
- .hotel.lk:Hotels
Thailand[edit]
Trinidad and Tobago[edit]
- 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
Türkiye[edit]
In Türkiye, domain registrations, including the registration of second-level domains is administrated byTRABİS.[5] There 22 active second-level domains under the.trTLD.[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.trfor commercial ventures,.edu.trfor academic institutions and.name.trfor personal use.[8]Türkiye second-level domains include:
- gov.tr(reserved for theGovernment of Turkeyand state institutions/organizations)
- mil.tr(reserved for theTurkish Armed Forces;retired in 2010 and replaced by tsk.tr)
- tsk.tr(reserved for theTurkish Armed Forces;used since 2010)
- k12.tr(reserved for schools approved by theMinistry of National Education)
- edu.tr(reserved for higher education institutions approved by theCouncil of Higher Education)
- av.tr(reserved for freelance lawyers, law firms and attorney partnerships)
- dr.tr(reserved for medical doctors, medical partnerships, hospitals, and healthcare services)
- bel.tr(reserved for provincial, district, and town municipal organizations and governments)
- pol.tr(reserved for theGeneral Directorate of Securityand police)
- kep.tr(reserved for Registered Electronic Mail Service Providers [KEPHS] authorized by theInformation and Communication Technologies Authority)
- com.tr(intended for commercial entities)
- net.tr(reserved for network operators/providers, as well as internet-related access services such as portals, e-mail, etc.)
- org.tr(reserved for nonprofit entities such as foundations, associations, and non-governmental organizations)
- info.tr(intended for informational websites)
- bbs.tr(reserved for entities providingBBSservices)
- nom.tr(reserved for individual/personal use)
- tv.tr(reserved for entities in the television industry)
- biz.tr(intended for commercial entities)
- tel.tr(reserved for use in connection with Turkish telephone numbers)
- gen.tr(general use)
- web.tr(general use)
- name.tr(reserved for individual/personal use)[8]
Ukraine[edit]
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[edit]
United States[edit]
A two-letter second-level domain is formally reserved for each U.S. state, federal territory, and the District of Columbia.
Zambia[edit]
Historic second-level domains[edit]
There are several second-level domains which are no longer available.
Australia[edit]
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.aufor general information,.otc.auand.telememo.aufor the X.400 mail systems.[9]
Canada[edit]
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[edit]
Historic second-level domains for France included: .tm.fr(for brands),.com.fr(for commercial use) and.asso.fr.[11][12]
The Netherlands[edit]
Historic second-level domains for the Netherlands included: .co.nl(for commercial use)[13][14]
Yugoslavia[edit]
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.yufor commercial enterprises;.org.yufor organizations and.cg.yufor residents of Montenegro. Only legal entities were allowed to register names under.yuand its second-level domains.[15]
Tuvalu[edit]
Historic second-level domains for Tuvalu included: co.tv
Legal issues[edit]
As a result of ICANN's generic top-level domain (gTLD) expansion,[16]the risk ofdomain squattinghas increased significantly. For example, based on current regulations, the registration of the gTLDs.olympicsor.redcrossis not allowed; however, the registration of sites such asolympics.exampleorredcross.exampleis 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.healthor.diet.healthcan be easily misused by companies and therefore are a potential threat to Internet users.[18]
See also[edit]
- 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[edit]
- ^"Useful information about.or.at domains".Retrieved29 October2014.
- ^"Domain registration".Retrieved29 October2014.
- ^"Principles and Grants".Retrieved29 October2014.
- ^"Sector-based.fr domains".Retrieved31 October2014.
- ^"Overview".Retrieved29 October2014.
- ^"Who could register which domain name?".Retrieved17 May2024.
- ^"Can an individual or a company in abroad register a".tr "domain name?".Retrieved17 May2024.
- ^ab"Who could register which domain name?".Retrieved17 May2024.
- ^"the australian second level domain name system".Retrieved31 October2014.
- ^"General Registration Rules, Version 3.21, February 5, 2015"(PDF).Archived fromthe original(PDF)on 2017-12-01.Retrieved18 November2017.
- ^"Useful information about.fr domains".Retrieved31 October2014.
- ^"ICANN-Registrar: French Domains with Accents".Retrieved31 October2014.
- ^"Commercial, national & international character with a.co.nl domain name".Retrieved25 January2016.
- ^".Co.NL WhoIS".Retrieved25 January2016.
- ^".RS - Republic of Serbia.ME - Republic of Montenegro (Former parts of Yugoslavia) Formerly.YU and.CS Country Codes".Retrieved31 October2014.
- ^"Delegated strings".Retrieved29 October2014.
- ^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.PMC3961808.PMID24598602.