Purpose of this document is: a) To establish the minimum acceptable characteristics for gaseous breathing oxygen and liquid breathing oxygen purchased or produced for cross-servicing NATO aircraft; b) To simplify the cross-servicing of aircraft gaseous oxygen systems through the adoption of standardized supply pressures, hoses, couplings and access clearance for the replenishment of those gaseous oxygen systems; and c) To increase the effectiveness of cross-servicing NATO aircraft by ensuring the minimum acceptable characteristics of charging hoses, couplings and access clearance for the replenishment of aircraft liquid oxygen systems.