Country code second-level domain

{{refimprove|date=December 2010}}

A country code second-level domain is a second-level domain to a country code top-level domain.{{citation needed|date=December 2010}} Such a domain may be reserved by a 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 domains {{mono|com}}, {{mono|net}}, and {{mono|org}}, which were intended for commercial entities, network operators, and non-profit organizations, respectively.

Many countries implement additional classes. For example, the United Kingdom (.uk) uses {{mono|co.uk}} for commercial purposes and {{mono|ac.uk}} for academic registrants. Brazil (.br) has a high number of predefined second-level domains, 140 as of 2021; they range from {{mono|com.br}} for commercial activities and {{mono|vet.br}} for veterinarians to {{mono|wiki.br}} for wikis (see .br § Second-level domains).{{ cite web | url=https://registro.br/dominio/categorias/ | title=Categorias de domínios .br | lang=pt-br | trans-title=Categories of .br domains | website=Registro.br | access-date=17 August 2021 }}