This United States Army dictionary, Field Manual FM 1-02.1 Operational Terms March 2021, constitutes approved Army doctrinal terminology for general use. The principal audience for this manual are all members of the profession of Arms. Commanders and staffs of Army headquarters serving as joint task force or multinational headquarters should also refer to applicable joint or multinational doctrine concerning the range of military operations and joint or multinational forces. Trainers and educators throughout the Army will also use this publication.