A priority system is when you are faced with multiple options, and you have to determine which is the most appropriate attack given your conditions: Foregoing a positional and staying the course, clipping or not clipping a DOT, determining if a buff/debuff has the time left to last through another set of moves, etc. As monks we have multiple options as such you have to place a priority on what occurs. So a priority system is what is used to determine what the best attack is for the situation that you are in. It's not limited to a narrow definition that you want to give it. Again, what you described before is a priority system.

I'm not saying that what you said was incorrect just that what you described is a priority system.