Registry lock provides your domain name with an extra layer of security protection. Once registry lock is enabled, transfer, registration info and DNS modification and deletion will be prohibited from the registry level. Disabling requires a strict offline verification process to effectively prevent domain names from unauthorized updates like modification, transfer or deletion.
Without enabling registry lock, the EPP status code in Whois will show ok (normal status); once enabled, the EPP status code in Whois will show Server Delete Prohibited, Server Update Prohibited or Server Transfer Prohibited.