officer in command of unit "B") as officer "A" would be seen as subverting the authority of the officer of unit "B". Depending on the situation or the standard procedure of the military organization, the lower-ranked member being ordered may choose to carry out the order anyway, or advise that it has to be cleared with his or her own chain of command first, which in this example would be with officer "B". Refusal to carry out an order is almost always considered insubordination; the only exception usually allowed is if the order itself is illegal (i.e., the person carrying out the order would be committing an illegal act). (See superior orders.) In addition, within combat units, line officers are in the chain of command, but staff officers in specialist fields (such as medical, dental, legal, supply, and chaplain) are not, except within their own specialty. For example, a medical officer in an infantry battalion would be responsible for the combat medics in that unit but would not be eligible to command the battalion or any of its subordinate units. The term is also used in a civilian management context describing comparable hierarchical structures of authority. Such structures are included in Fire Departments, Police Departments, and other organizations that have a paramilitary command or power structure. Sociology In sociology, command hierarchy is seen as the most visible element of a "power network." In this model, social capital is viewed as being mobilized in response to orders that move through the hierarchy leading to the phrase "command and control". Features Regardless of the degree of control or results achieved, and regardless of how the hierarchy is justified and rationalized, certain aspects of a command hierarchy tend to be similar: rank – especially military rank – "who outranks whom" in the power structure unity of command – each member of the hierarchy has one and only one superior, precluding the possibility of contradictory orders strict accountability – those who issue orders are responsible for the consequences, not those who carry them out (with the exception of illegal orders, as previously noted) strict feedback rules – complaints go up the hierarchy to those with power to deal with them, not down to those who do not have that power detailed rules for decision making – what criteria apply and when standardized language and terminology some ethics and key beliefs in common, usually enforced