I am using an Air Canada PMDG 77W and set the ATC Parking Code to AC, as ACA doesn't work. After doing so, I get a mixture of Air Canada and Kuwait Airways containers. It is worth noting out of the ten total containers, 7 of them may be Air Canada, while three may be Kuwait Airways. never had this problem before so not really sure what to do about the mixed containers with the ATC Parking Codes.
[fltsim.8]
title=Boeing 777-333/ER Air Canada C-FITL
sim=B777-300ER
model=
panel=
sound=
texture=C-FITL
atc_airline=AIR CANADA
atc_id=C-FITL
atc_flight_number=1
atc_parking_codes=AC
atc_model=777-300ER
atc_heavy=1
atc_parking_types=GATE
atc_type=BOEING
ui_createdby=PMDG
ui_manufacturer=Boeing
ui_type=777-333/ER
ui_typerole=777-333/ER
ui_variation=Air Canada (C-FITL)
airline_name=Air Canada