In NIC.UA it is possible to register regional Nikolaev domains: .mk.ua and .nikolaev.ua.
While choosing a free domain .mk.ua, .nikolaev.ua, you should remember that the mirroring rule applies to these domains. For example, if the domain example4you.mk.ua already existed, then the mirror domain, example4you.nikolaev.ua, would be automatically reserved by the .mk.ua registry for the owner of the already occupied example4you.mk.ua.
It is also interesting that while checking the second domain example4you.nikolaev.ua in WHOIS, it will be displayed as available for registration, but if a third party (other than the current owner of the occupied example4you.mk.ua) tries to register example4you.nikolaev.ua, the registry will reject this request. Another important feature is that both mirror domains must be served by the same registrar.
If both mirror domains .mk.ua and .nikolaev.ua are free, to register them, it is enough to place an order for 2 domains at once.
When one of the domains is already taken, to register the second, contact our support and we will check everything and advise you on further actions.
The rules of registration of Nikolaev domains can be found on the official page of the Registry Administrator .mk.ua.