text: Appendix B
  B-19. Kill Box Types. The following kill box color definitions are specific to munition delivery methods (to
  include air-to-surface only or air-to-surface and surface-to-surface).
  * Blue Kill Box. The primary purpose of a blue kill box is to facilitate the attack of surface targets
  with air-to-surface munitions without further coordination with the AO commander see figure B-
  5.The blue kill box extends from the surface to a ceiling altitude. Altitude is the vertical distance
  of a level, a point or an object considered as a point, measured from mean sea level or heigh
  above ellipsoid. Indirect fire munitions impacting within or passing through an active blue kill
  box must be coordinated with the designated airspace control element, kill box coordinator, or the
  aircrew on station in the blue kill box.
  * Purple Kill Box. The purple kill box enables joint fires in the kill box to maximize potential for
  engaging targets. The primary purpose of a purple kill box is to facilitate the attack of surface
  targets with subsurface-to-surface, surface-to-surface, and air-to-surface munitions without further
  coordination with the AO commander. The purple kill box contains an altitude floor below which
  aircraft will not fly, that enables subsurface-to-surface and surface-to-surface fires. Indirect fires
  that remain beneath the ACM floor do not require further coordination; however, airspace
  coordination along the munition flight path outside the kill box must still occur.
  B-20. Kill Box Operating Status Terminology.
  * Established. A status that identifies the kill box is published on the ACO.
  * Effective Time. The scheduled date and time of the kill box on the ACO.
   Active. There is activity in the kill box. A descriptor identifying an established kill box has a
  fires and airspace status affecting aircraft and fires operating in the kill box.
   Inactive. There is no activity in the kill box. A descriptor identifying an established kill box
  is without a fires and airspace status affecting fires or aircraft operating in the kill box.
  Additional coordination is required to activate an inactive kill box.
  * Cancelled. The kill box is no longer established and is deleted from the ACO.
  B-21. Kill Box Fires Status and Airspace Status Terminology. An active kill box status is described in two
  parts: fires and airspace. The fires status addresses effects in the kill box’s target area. The airspace status
  addresses the availability of and restrictions for using the airspace above the target area.
  B-22. Fires Status. An active kill box’s fires status is either HOT or COLD.
  * HOT. A status that describes a kill box or portion of a kill box where fires are permitted without
  further coordination.
  * COLD. A status that describes a kill box or portion of a kill box where fires are not permitted
  without further coordination.
  B-23. Airspace Status. An active kill box’s airspace status is either OPEN or CLOSED.
  * OPEN. A status that describes a kill box or portions of a kill box where aircraft may be approved
  to operate inside the kill box ACM or designated segments.
  * CLOSED. A status that describes a kill box or portion of a kill box that restricts aircraft from
  operating within the confines of the kill box or designated segments. Indirect subsurface-to-surface
  and surface-to-surface fires trajectories may transit through them.
  B-24. Airspace Control Element. The airspace control element is the assigned tactical C2 echelon assigned
  to control a given kill box on the ACO. All airspace users should contact the assigned airspace control element
  prior to entry into a kill box. When the kill box is inactive, or active without a kill box coordinator, the
  assigned airspace control element is responsible for coordination regarding the kill box.
  B-25. A kill box facilitates the expeditious air-to-surface lethal attack of targets (such attacks can be
  augmented with surface-to-surface indirect fires). A "blue" kill box permits air-to-surface fires within its
  boundaries and typically extends from the surface to a ceiling altitude; a "purple" kill box within its boundary.
  B-26. Kill Box Lateral Dimensions and Subdivision. The lateral dimensions of a kill box should be defined
  using GARS. Using GARS cells, quadrants, and keypads to define kill boxes facilitates airspace and fires
  joint integration and deconfliction by the assigned airspace control elements. For more information on kill
  box employment see JP 3-09 and ATP 3-09.34.