ATCs assert that the nonstandard use of such lexical items frequently occur during Route or En-route Clearance while Pilots confirm that these transpire during Takeoff Clearance, Altitude Clearance, Approach Clearance, and Landing Clearance.
the nonstandard use of Aviation Phraseology in this study shows nonconformity in the efforts of the International Civil Aviation Organization to provide "maximum clarity, brevity, and unambiguity".