text: Fire Support Coordination Measures
  * Visibility. Observation from seaward is a desirable feature for zones of fire since it permits a ship
  to deliver more accurate and rapid fire.
  * Accessibility to Fire. The zones of fire must be accessible to the trajectory of the FS ship(s)
  assigned to the zone.
  B-47. A FA unit's higher HQ may also assign a FA unit a ZF. The ZF for artillery units assigned to a maneuver
  unit or assigned the DS support relationship corresponds to the AO of the parent or supported unit. The ZF
  for an artillery unit assigned the R support relationship corresponds to the ZF of the reinforced artillery unit.
  The ZF for an artillery unit assigned the GSR support relationship corresponds to the AO of the supported
  unit including the zones of fire of the reinforced artillery unit. The ZF for an artillery unit assigned the GS
  relationship corresponds to the AO of the supported unit. For more information on amphibious operations
  see JP 3-02.
  FINAL PROTECTIVE FIRE
  B-48. Final protective fire is an immediately available, prearranged barrier of fire designed to impede enemy
  movement across defensive line or areas (JP 3-09.3). An FPF provides continuous fires on a planned target.
  FPFs should be integrated with maneuver crew served weapons final protective lines. When the adversary
  initiates the final assault into a defensive position, the defending unit initiates its FPFs to kill adversary forces
  and suppress armored vehicles.
  B-49. The FPF consists of a single black line. Two anchor points, one at each end of the line, determine the
  line's length and orientation. The target number followed by the firing unit responsible and the caliber of that
  unit's weapons below the line. Figure B-12 portrays the assigned FPFs of Alpha Battery, 1st BN 16th FA
  (155-mm), a priority target for that unit.
  Figure B-12. Final protective fire example
  BOUNDARIES
  B-50. A boundary is a line that delineates surface areas for the purpose of facilitating coordination and
  deconfliction of operations between adjacent units, formations, or areas (JP 3-0). Boundaries divide up areas
  of operation and define responsibility for clearance of fires. Boundaries are both permissive and restrictive
  in nature (see figure B-13 on page B-18).
  B-51. They are permissive in that a maneuver commander, unless otherwise restricted, enjoys designation of
  priority, effects, and timing of fire and maneuver within their own boundaries. Thus, units may execute joint
  fires without close coordination with neighboring units unless otherwise restricted. They are restrictive in
  that normally units do not fire across adjacent or forward boundaries unless the fires are coordinated with the