Country code second-level domain
Encyclopedia
A country code second-level domain (ccSLD) is a second-level domain
to a country code top-level domain
. A ccSLD may be reserved by the domain name registry
for the registration of third-level domains or assigned to a third party as a subdomain
.
Many country code domain registries implement domain name classes at the second level underneath their ccTLD, such as are present in the original generic top-level domain
s com, net, and org, which were intended for commercial entities, network operators, and non-profit organizations, respectively.
Many countries implement additional classes as well. For example, the United Kingdom
(uk
) uses co.uk
for commercial purposes and ac.uk
for academic registrants.
Brazil (br
) has a high number of restricted second-level domains, currently amounting to 67; they range from com.br for commercial activities, vet.br for veterinarians, to wiki.br for wikis.
Second-level domain
In the Domain Name System hierarchy, a second-level domain is a domain that is directly below a top-level domain . For example, in example.com, example is the second-level domain of the .com TLD....
to a country code top-level domain
Country code top-level domain
A country code top-level domain is an Internet top-level domain generally used or reserved for a country, a sovereign state, or a dependent territory....
. A ccSLD may be reserved by the domain name registry
Domain name registry
A domain name registry is a database of all domain names registered in a top-level domain. A registry operator, also called a network information center , is the part of the Domain Name System of the Internet that keeps the database of domain names, and generates the zone files which convert...
for the registration of third-level domains or assigned to a third party as a subdomain
Subdomain
In the Domain Name System hierarchy, a subdomain is a domain that is part of a larger domain.- Overview :The Domain Name System has a tree structure or hierarchy, with each node on the tree being a domain name. A subdomain is a domain that is part of a larger domain, the only domain that is not...
.
Many country code domain registries implement domain name classes at the second level underneath their ccTLD, such as are present in the original generic top-level domain
Top-level domain
A top-level domain is one of the domains at the highest level in the hierarchical Domain Name System of the Internet. 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 label of a...
s com, net, and org, which were intended for commercial entities, network operators, and non-profit organizations, respectively.
Many countries implement additional classes as well. For example, the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
(uk
.uk
.uk is the Internet country code top-level domain for the United Kingdom. , it is the fourth most popular top-level domain worldwide , with over 9.5 million registrations....
) uses co.uk
.co (second level)
.co is a second-level domain analogous to .com in a number of countries, in which registrants may register second-level domains of the form .co.xx, where xx is the ccTLD .co (abbreviation of commercial) is a second-level domain analogous to .com (in a strictly second-level sense) in a number of...
for commercial purposes and ac.uk
.ac (second level)
.ac is a second level domain for academic establishments, such as universities, colleges and research institutes. Many countries use .edu for the same purpose, for example .edu.au in Australia, .edu.my in Malaysia...
for academic registrants.
Brazil (br
.br
.br is the Internet country code top-level domain for Brazil. It was administered by the Brazilian Internet Steering Committee until 2005 when it started being administered by Brazilian Network Information Center . A local contact is required for any registration...
) has a high number of restricted second-level domains, currently amounting to 67; they range from com.br for commercial activities, vet.br for veterinarians, to wiki.br for wikis.