Eu não sei os detalhes exatos ou implementações, mas o meu entendimento é que ele gira em torno do EPP - Extensible Provisioning Protocol
The motivation for the creation of EPP was to create a robust and flexible protocol that could provide communication between domain name registries and domain name registrars. These transactions are required whenever a domain name is registered or renewed, thereby also preventing domain hijacking. Prior to its introduction, registries had no uniform approach, and many different proprietary interfaces existed.