Category 1 Names – The Conditions.
ICANN* receives input from governments via the Governmental Advisory Committee. The GAC issues advice to the ICANN Board of Directors regarding New gTLD applications. GAC Advice is intended to identify applications that are “problematic,” e.g., that potentially violate national law or raise sensitivities. Read more detail here | read an excellent article about this | read the full PDF from ICANN
Additionally, each Registry has a reserved names list, there are circa 135,000+ reserved names, each Registry operates their own Whois and their systems may tell us that a domain is not registered, in that regard the Whois response is correct – nonetheless the name it is not available since it is on a reserved list.
In some cases the system may allow names that are not available to be registered. This is outside the control of Registrars and Resellers. We are monitoring WHOIS evolution on a constant basis and will advise clients and customers just as soon as there is some improvement / clarity.