GSX has it's entirely separate grouping convention, which is far more flexible than the limited FSX type. You can have a sample of it at places like KLAX, CYVR or KJFK, when the GSX names makes selecting a parking way easier and more realistic that what FSX allows.
Also, many developers (including us, but not only) play with the AFCAD parking type in order to control the kind of ground vehicles (or to get rid of them) at a parking, so what you might see on the AFCAD might not be so useful.