OCN is short for Optimal City Number... I don't recall exactly what it is in RoX, but basically, if you have 12 or more cities Communism is a good bet... It will allow you to be a very effective conqueror since no matter how far you conquer, as long as you build the SPHQ and keep building courthouses and police stations all over the place every now and then, corruption will be at levels you can live with in your new conquests... This will allow you to make good use of anything you conquer, and you will be able to quickly establish newly conquered cities as army bases to use for continued conquest...
btw everyone, about the proposed RoX GOTM, I'm gonna get in gear soon and the first game will begin March 1st. The game will be called the RoX Monthly Challenge (RMC), and I will be the main organizer for now. For the first game, I will want two people to help me organize and judge the game. I'll release more details about the game as we draw closer to the start of RMC1. Meanwhile I will only tell you that the nations I'm considering for it are Arabia, Korea, Mexico, Ethiopia and Inca, each of course with a completely different set of goals and bonuses. I have not yet decided if the goals for each game will be focused on a certain aspect of the game, or spread broadly to allow for different styles of play... Perhaps every RMC will be different.