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 {{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|uk]]) uses {{mono|[[.co.uk|co.uk]]}} for commercial purposes and {{mono|[[.ac.uk|ac.uk]]}} for academic registrants. Brazil ([[.br|br]]) has a high number of restrictedpredefined second-level domains, 67140 as of 20112021;<ref>[http://registro.br/info/dpn.html Registro.br] 4 February 2011</ref> 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|.br § Second-level domains]]).<ref>{{ cite web | url=httphttps://registro.br/infodominio/dpn.htmlcategorias/ | title=RegistroCategorias de domínios .br |author lang=pt-br |date trans-title=Categories of .br domains |publisher website=Registro.br |accessdate access-date=517 August October2021 2016}}</ref>
