Overview
The .CO Registry is built on the CentralNic Shared Registry System (SRS), deployed as a fully independent instance. The system is object-oriented: Registrars create and manage three types of objects — domains, contacts, and hosts.
Object Types
- Domain objects (RFC 5731) — represent registered domain names.
- Host objects (RFC 5732) — represent nameserver records (both in-bailiwick and out-of-bailiwick).
- Contact objects (RFC 5733) — represent registrant, administrative, technical, and billing contacts.
Object Sponsorship
Every object in the SRS is associated with exactly one Registrar, who is called the 'sponsor' of that object. Sponsors can create, update, and delete objects they sponsor. Objects can be transferred between Registrars.
EPP Protocol
All programmatic management is via EPP (RFC 5730) — a stateful XML protocol over TLS-secured TCP. All EPP commands are atomic (no partial success/failure) and designed to be idempotent.
Data Flows
When a Registrar submits a domain:create command, the system validates the request, deducts the fee from the Registrar's balance, creates the domain object, and publishes DNS delegation records. Changes typically propagate within seconds.