My "old" and "dated" experience is that I started with the airline and then moved to Royal flight which at the time was I seem to recall cost center 956...no idea what is going on now. or anyone there.
I should add the lateral move was at the time rare...I got transferred without leaving KOSA which was also rare. it only happened I think because I had a special assignment to train one of the Ladin kids (grin). she is now a captain for a major European airline