Although your domains are already securely managed, this free option allows you to lock your domain at the Registry level. While in this state the domain registration cannot be transferred, nor can other aspects of the domain be altered (such as your domain's name servers, contact information, and ownership).
When a domain is locked you cannot modify the name servers or contact information. If you need to update name servers or other information, please unlock your domain name first. Selected domains will be unlocked within 15 minutes.
To lock or unlock your domain name:
Step 1:
Log in to the DomainNameCom.com Account Manager.
Step 2:
Select Manage Domains from the Domain Names dropdown menu or the Manage Your Account list.
Step 3:
Select the domain name you wish to modify by checking the box next to it, then click the Set Locking button.
Step 4:
Select the radio button for Locked or Unlocked and click the Save Changes button.
More about registering and managing domain names ...
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