text: Appendix B
  Figure B-3. Free-fire area example
  GRIDDED REFERENCE GRAPHIC
  B-15. A gridded reference graphic (GRG) (see figure B-4 for an example) are detailed gridded maps or
  imagery that have a military grid reference system grid and may contain information including building
  numbers, FSCMs, phase lines, helicopter landing zones, and named areas of interest. It is the responsibility
  of the ground unit that owns a particular OA to produce GRGs for that area, ensure dissemination to
  subordinate, adjacent, and higher echelons, and maintain version control on the products as they are updated
  or revised. The developing unit should consider selecting grid sectors based on what the aircrew or aircraft
  sensors can most easily see such as rivers, road junctions, buildings, and bridges. For more information on
  the GRG see JP 3-09.3 Below are recommendations for GRG creation:
  * Ensure the collection manager provides the clearest and most recent image of the area.
  * Imagery should contain a north arrow and the picture should be oriented north-up whenever
  possible.
  * Easting and northing lines should be labeled at the top and left side of the GRG, respectively.
  * Buildings may be numbered from northwest to southeast for large area GRGs, or from the
  objective building clockwise for smaller scale single-objective GRGs.