This paper distills and organizes facts about cartels from about 20 European Commission decisions over 2000-2004. It describes the properties of a collusive outcome in terms of the setting of price and a market allocation, monitoring of agreements with respect to price but more importantly sales, punishment methods for enforcing an agreement and also the use of buy-backs to compensate cartel members, methods for responding to external disruptions from non-cartel suppliers and handling over-zealous sales representatives, and operational procedures in terms of the frequency of meetings and the cartel's organizational structure.