1 To authorise hardware as fit for use.
2 To authorise person to receive classified information.
3 To rectify stoppage in automatic weapon.
4 To unload weapon and demonstrate no ammunition remains.
5 To empty core store, register or other memory device.
6 In flight operations, authorised to take off, land or make other manoeuvre under ground control.
7 En route, to pass over waypoint.
8 To destroy all hostile aircraft in given airspace.
9 Of local sky, devoid of clouds (“the *”), but may be above or between cloud layers.
10 To clean piston engine; see cleaning.
11 To fly out of a local area, eg a flying display.
12 Not secure [communications].