Prices of registration

Prices of domain registrations are set by each registry.
Third-level domains

Domain name registries may also impose a system of third-level domains on users. DENIC, the registry for Germany (.de), does not impose third level domains. AFNIC, the registry for France (.fr), has some third level domains, but not all registrants have to use them, and Nominet UK, the registry for the United Kingdom (.uk), requires all names to have a third level domain (e.g. .co.uk or .org.uk)

Domain Sub-Registration

Registrants of second-level domains sometimes act as a registry by offering sub-registrations to their registration. For example, registrations to .fami.ly are offered by the registrant of fami.ly and not by GPTC, the registry for Libya