Military Classification is a system used by the military to categorize personnel according to their roles and responsibilities. The two crossword solutions, ACTIVE (6 letters) and ONEA (4 letters), refer to two of these classifications. ACTIVE is a term used to describe personnel who are currently serving in the military, while ONEA stands for Officer Non-Commissioned Extended Appointment, which is a type of appointment given to officers who have been promoted to a higher rank.