Child Name Servers or Glue Records re Name Servers which are registered with the Registry under your domain name. You have to register Name servers with the Registry, before you can use them as Name Servers for registering other domain names. Child Name Servers can be registered only by the owner of the domain name under which they are registered.
A Child Name Server ns2.xyz.com can only be registered by the Owner of xyz.com.
Registering and Managing Child Name Servers
Login to your Control Panel, search for the domain name and proceed to the Order Information view.
Click the Child Name Servers link.
Here, you may:
Add a Child Name Server
Enter the Host Name of the Child Name Server you wish to add in the Host Name box, mention its IP Address (IPv4 or IPv6) and click the Save button.
For yourdomainname.com, you may use the Host Name as ns1.yourdomainname.com and an IPv4 IP Address as 111.222.333.444.
yourdomainname.biz could have the Host Name as dns1.yourdomainname.biz and an IPv6 IP Address as 2001:0db8:0:0:0:0:1428:57ab.
Modify a Child Name Server
Modifying the Hostname: Make the modifications in the Host Name textbox and click the Save button.
Modifying the IP Address: Make the modifications in the IP Address textbox and click the Save button.
Delete a Child Name Server
Click the Delete link to delete individual Child Name Servers.