Also known as area of separation; neutral space created by withdrawal of both hostile parties; a demilitarised zone where the parties have agreed not to deploy military forces; the cease-fire lines, marked and often fenced or wired on either side of the buffer zone, indicate the agreed forward limits of the contending forces; the cease-fire lines are observed, patrolled and perhaps occupied by the peace-keeping force; the buffer zone itself may be placed under the control of a PKO