Cite from: http://labs.centralnic.com/epp/status.php
EPP(Extensible Provisioning Protocol) Status Codes
CentralNic's EPP server implementation is based on the following Internet RFCs:
* RFC 4930 (Extensible Provisioning Protocol)
* RFC 4931 (Domain Name Mapping)
* RFC 4932 (Host Mapping)
* RFC 4933 (Contact Mapping)
* RFC 4934 (Transport Over TCP)
* RFC 3735 (Guidelines for Extending EPP)
* RFC 3915 (Domain Registry Grace Period Mapping)
* RFC 4310 (Domain Name System (DNS) Security Extensions Mapping)
These RFCs defined a range of status codes for objects provisioned by EPP servers. These status codes are primarily applicable to domain names.
This document explains what each status code means, and how it is implemented in our registry system.
Client-assigned vs. Server-assigned
Status codes fall into two categories: client-assigned codes are managed by the registrar, whereas server-assigned codes are managed by the registry.
Client-assigned codes are enforced by the registry on behalf of the registrar, and can be arbitrarily added to or removed from an object by the registrar. Conversely, server-assigned codes may only be added to or removed from an object by the registry. They take precedence over client-assigned status codes.
List of Client-assigned Status Codes
* clientHold: This status allows a registrar to remove a domain name from the DNS - if, for example, payment has not been received from the registrant. This status has no effect on the registrar's ability to update, transfer, delete or renew the domain - the only effect is on the domain's presence in the DNS.
* clientTransferProhibited: This status code instructs the registry to reject any requests from other registrars for the object to be transferred into their sponsorship. This status has no effect on the registrar's ability to update, delete, or renew the domain.
* clientUpdateProhibited: This status code instructs the registry to reject any requests to update the details of the object by the registrar. The purpose of this status is to provide a "safety lock" that must be explicitly opened before a object can be updated.
* clientDeleteProhibited: This status code works in a similar way to clientUpdateProhibited - it instructs the registry to refuse any request to delete the object. The object may still be deleted by the registry if it expires.
* clientRenewProhibited: This status code instructs the registry not to automatically renew the domain name upon expiry. The registrar may still renew the domain name at its discretion. This status is equivalent to the "Declined Renewal" status on non-GRS domain names.

