text: Appendix B
  * When an enemy force within the NFA engages a friendly force and the engaged commander
  determines there is a requirement for immediate protection and responds with the minimal force
  needed to defend the force.
  B-34. Any size unit may establish NFAs. If possible, the NFA is established on identifiable terrain. It may
  also be located by a series of grids or by a radius from a center point.
  B-35. The NFA is graphically portrayed (see figure B-7) as an area outlined with a solid black line with black
  diagonal lines inside. The letters "NFA" are within, followed by the establishing HQ and the effective date-
  time group.
  Figure B-7. No fire area example
  RESTRICTIVE FIRE AREA
  B-36. A restrictive fire area is a location in which specific restrictions are imposed and into which fires that
  exceed those restrictions will not be delivered without coordination with the establishing headquarters (JP 3-
  09).