text: Tactical Control Measures
  Figure A-34. Task force engagement areas
  Final Protective Fire
  A-75. Final protective fire is an immediately available,
  prearranged barrier of fire designed to impede enemy movement
  across defensive lines or areas (JP 3-09.3). Both direct and
  indirect fire weapons can provide final protective fires (FPFs). A
  commander can only assign each firing battery or platoon a
  single FPF. Firing units should lay on their FPFs (or other
  assigned priority targets) but do not “engage” or fire them unless
  directed. A FPF is a priority target for an element or system, and
  those fire units engage that target when they are not engaged in
  other fire missions. When an enemy force initiates its final
  Figure A-35. Final protective fire
  assault into a defensive position, the defending unit initiates its
  FPFs to engage enemy infantry soldiers and armored vehicles. Figure A-35 depicts an FPF to be fired by
  A/1-16 Field Artillery.