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.
The term may also refer to command and control systems within a military system. The 1988 NATO definition reads: Command and control is the exercise of authority and direction by a properly designated [individual] over assigned [resources] in the accomplishment of a [common goal].