There are multiple different locks that can be applied to a domain name held in the Astutium/ARP system. Each one has a REGISTRAR and REGISTRANT variety.
The REGISTRAR version means that it was applied by the registration provider, and cannot be overriden by the domain owner.
The REGISTRANT version was applied by the domain owner, and can be removed by them at any time.
| Lock Name | Description |
| _DELETE | This domain cannot be deleted. This stops the domain from being deleted prematurely by accident. It does not stop the domain from being removed due to expiry. |
| _HOLD | This domain will not appear in the DNS. This is one form of suspending a domain registration, all queries for all different services will be met with 'Server Not Found'. |
| _RENEW | This domain cannot be renewed. This stops the domain being renewed, this is often a method to make sure that a domain is not kept beyond its current term. |
| _TRANSFER | This domain cannot be transferred to another registrar. When this lock is set all transfer requests - even with a valid EPP Transfer Authorisation Code will be denied. This stops your domain from being transferred by accident. |
| _UPDATE | The domain cannot be updated, this includes contacts and nameserver details. This can be used to prevent unauthorised changes to your domain name. |
Each of the Lock Names in the above table will be prefixed with either REGISTRAR or REGISTRANT as detailled above.
