Modifier 57 (decision for surgery) is added to an E/M code if the surgeon sees the patient and then, based upon the evaluation of the patient, decides to proceed with surgery either the same or the following day.
The US Department of Defense Dictionary of Military and Associated Terms. defines command and control as: The exercise of authority and direction by a properly designated commander over assigned and attached forces in the accomplishment of the mission.
Definition of chain of command. : a series of executive positions in order of authority a military chain of command.