When updating a domain with new nameservers, additional validity checks may be applied, if the domain and its nameservers are governed by the same registry.
In such cases, many registries will check whether the nameservers to be used are correctly set up as host objects (or glue records, depending on which method is employed by the registry). A-records, subdomains, etc. will not be accepted.
Examples:
- Using a .com nameserver on a .com domain: Check applies, host object is required as it is the same TLD.
- Using a .net nameserver on a .com domain: Check applies, host object is required as both TLDs are run by the same registry (VeriSign).
- Using a .org nameserver on a .com domain: Check doesn't apply, A-record (etc.) sufficient as registries differ (PIR vs. VeriSign).