| Subject | English | Thesaurus |
| avia. | air traffic control clearance | Authorization for an aircraft to proceed under conditions specified by an air traffic control unit. Note 1.— For convenience, the term 'air traffic control clearance' is frequently abbreviated to 'clearance' when used in appropriate contexts. Note 2.— The abbreviated term 'clearance' may be prefixed by the words 'taxi', 'take-off', 'departure', 'en route', 'approach' or 'landing' to indicate the particular portion of flight to which the air traffic control clearance relates. |
| avia. | air traffic control instruction | Directives issued by air traffic control for the purpose of requiring a pilot to take a specific action. |
| avia. | air traffic control service | A service provided for the purpose of: 1. preventing collisions: 1)between aircraft, and 2)on the manoeuvring area between aircraft and obstructions; and 2. expediting and maintaining an orderly flow of air traffic. |
| avia. | air traffic control unit | A generic term meaning variously, area control centre, approach control unit or aerodrome control tower. |
| transp., abbr. | Work Zone Traffic Control | WZTC |
| transp., abbr. | Work Zone Traffic Control Plan | WZTCP |