Physical verification of all contingent owned stores, equipment and vehicles and UN owned accountable items upon rotation of a contingent of change in Commanding Officer; the actual amount of the reimbursement for COE is based on the 'marching-in survey' (done when the contingent enters the mission area), and on the 'marching-out survey' (in the case of equipment/stores deployed for less than four years); these surveys are carried out by the contingent as well as by UN experts who assess the actual value of the equipment as it enters and leaves the mission area and are used by the UN as a basis for settlement of government claims for reimbursement.