From HandWiki - Reading time: 1 min
REGISTRAR-LOCK is not the same as REGISTRY-LOCK.[1]
REGISTRY-LOCK is a strong security feature implemented at the registry level that is used to prevent unauthorized changes to a domain [2] name. When a domain name has been locked at the registry, an agent of the sponsoring registrar must transmit a request to the registry to unlock the domain name. The agent of the sponsoring registrar requesting that the domain name be unlocked is subsequently contacted via a phone call by the registry and required to provide a secret passphrase over the phone for the domain name to be unlocked. This is an added layer of security that can be used to [3]protect strategic domain names.
When a domain name is protected by REGISTRY-LOCK at the registry level the domain name will have the status code "ServerUpdateProhibited."[4]