There's the alignment which pilots perform on their gyroscopes, because a readout of heading can drift away from the compass heading over time. The misalignment results in beacon directions being a few degrees off.
There's also the job of the installer, who must align readouts with true plumb and horizon. Does he adjust position of the gyroscope or position of the sensor?
Anyway it looks as though it's necessary to distinguish one type of misalignment from another.