How does an FBO refer to the parking spots on the ramp?
From the airports I've flown into, it's usually, you're just guided into a spot, and most often, there aren't any lines there, mainly since an FBO should be able to generally serve something as small as a Cessna, to a Gulfstream, or bigger. Flight School Ramps might have painted lines and dedicated parking for their fleet, but they know who will be parking there and what type.