If its not part of the long block its a bolt on..
LONG BLOCK ENGINES HAVE THE FOLLOWING INCLUDED.
BLOCK, CRANKSHAFT, PISTONS, RINGS, MAIN BEARINGS, ROD BEARINGS, CAM BEARINGS, CAMSHAFT, TIMING CHAIN, SPROCKETS, LIFTERS, PUSH RODS, ROCKER ARMS, C...YLINDER HEADS, OIL PUMP, OIL SCREEN, AND GASKET SET.
so to really heat this up, is a different supercharger installed on an engine with a factory supercharger considered a bolt on or a power adder... technically I think that is even a bolt on unless an intake is not considered a bolt on
That one has always been a bit of a 'grey area'...technically speaking a blower or turbo swap on a car that came from the factory with a blower or turbo should still fall under the 'bolt on' category but the discussion might become a little interesting when talking about going from say an Roots type supercharger to a centrifugal
This is the best definition then:
Anything that doesn`t touch motor oil and is not considered a power adder such as supercharger, turbo or nitrous (unless factory installed).
Either way, its damn fast and who really cares, run what you brought.