“ The medal shall be awarded only for operations for which no other United States service medal is approved. For operations in which personnel of only one Military Department or the Coast Guard participate, the medal shall be awarded only if there is no other suitable award available to the department or the Coast Guard. No more than one medal shall be awarded to any one person, but for each succeeding operation justifying such award a suitable device may be awarded to be worn on the medal or ribbon as prescribed by appropriate regulations. ”