The functional level of the DC on which the modification is taking place is at least DS_BEHAVIOR_WIN2012.

The object has class computer or server (or a subclass of computer or server).

In AD DS, the value of the msDS-AdditionalDnsHostName attribute being written is in the following format: anyDnsLabel.suffix, where anyDnsLabel is a valid DNS name label, and suffix matches one of the values of msDS-AllowedDNSSuffixes on the domain NC root (if any).

The requester must have the Validated-MS-DS-Additional-DNS-Host-Name validated write right.