MARINE CORPS MANUAL 1100.4 is all about fraternization policies of the Marine Corps. This is an unusual term that is used to describe personal and business relationships between Marines holding different ranks and positions. This implies that when relations between Marines exceed formal relations as Marines, fraternization is believed to have come into existence. Under this policy, commanders are instructed to take a close look at each of these individual cases. He has to verify if there is a compromise of the chain of command and if there is an evidence of partiality. Get MARINE CORPS MANUAL 1100.4 here to get the details of this manual.