As I understand it, it triggers on the atc_ident in aircraft.cfg of the aircraft used?
Nothing in the aircraft.cfg affects the choice of the ground operator, and surely not the atc_ident (nowhere the documentation every says this). The only thing in the aircraft.cfg file that affects GSX is the atc_parking_codes, which affects ONLY the choice of containers logos, not the ground operator itself.
Yes, I know, excuse me for not knowing the exact field names.
So allow me to ask the question for help again, instead of being told off on field name details.
As it stands, following the manual I can get custom handling and catering to work per gate where I'm parked at, but not via the rules files (icao-prefix or atc_parking_codes) as stated in the manual.
So any help, for instance a consice step by step, would help me a lot. Can you provide this please?