Clandestine HUMINT (HUMan INTelligence) includes a wide range of espionage sources. This includes the classic spy (called, by professionals, asset or agent) who collects intelligence, but also couriers and other personnel, who handle their secure communications. Other support personnel include access agents who may arrange the contact between the potential spy, and the case officer who recruits them. The recruiter and supervising agent may be different people. Large espionage networks may be composed of multiple levels of spies, support personnel, and supervisors. Espionage networks are usually organized on a cell system, where each clandestine operator knows the people in his own cell, perhaps the external case officer, and an emergency method, not necessarily a person, to contact higher