text: Tactical Control Measures
  Figure A-2. Division AO with single boundary and contiguous BCT assigned areas
  Assembly Areas
  A-8. An assembly area is an area a unit occupies to prepare for an operation. Units of all types and
  echelons can be assigned assembly areas. In figure A-3 on page A-4, are examples of multiple units
  occupying one assembly area is a graphical shortcut taken when the map scale makes depiction of multiple
  assembly areas unreadable. In reality, the higher echelon commander would subdivide ASSEMBLY AREA
  THOMAS into two smaller assembly areas, one for each unit. A unit assembly area is normally within the
  assigned area of a higher headquarters and are typically noncontiguous. This means that a unit has the same
  responsibilities within its assigned assembly area as it has for any other assigned area.
  A-9. A tactical assembly area is an area that is generally out of the reach of light artillery and the location
  where units make final preparations (precombat checks and inspections) and rest, prior to moving to the line
  of departure (JP 3-35). Tactical assembly areas are where enemy contact is likely and the commitment of a
  unit into combat is possible or anticipated. Examples of tactical assembly areas include locations occupied
  by units designated as tactical reserves, by units after completing a rearward passage of lines, temporarily by
  units during tactical movement, and by units during reconstitution. Units in tactical assembly areas are
  typically preparing to move forward to execute a forward passage of lines followed by offensive operations
  or have been assigned a reserve mission by their higher commander.
  A-10. Planning for, occupying, and departing an assembly area is difficult and time consuming and requires
  careful consideration. Ideally, an assembly area provides—
  * Concealment from air and ground observation.
  * Adequate entrances, exits, and internal routes.
  * Space for dispersion