In article <20170704233315.AAA7D7D84127@xxxxxxxxxxxxxxx> you write: >As to whether a class has a parallel heirachy or not depends on >how we define the use of the class. It hardly matters, because there's no practical way to bootstrap a new class. If all classes have the same root, the root servers for any new class are the same as the ICANN managed root, and short of an implusible revolt by the root server operators (one of which is of course ICANN), they'll have the same management issues that the IN tree does. Or if they don't have the same root, it's just another alt root, and we know where that leads. R's, John PS: I would also note that several special use TLDs do things you can't even express in the DNS. When you resolve a .onion name, you don't get an rrset, you get an open socket.