I was thinking about this one today. We have adhesive backed stickers with our fire department logo on them and occasionally slap them inside equipment locker doors on other fire department trucks. They come off easily so it’s harmless. I was reminded on back in the 80’s my wife was a T38 instructor pilot at Columbus AFB, MD (I was a civil engineer). The T38’s would make stops for fuel at Little Rock. The guys who fueled the aircraft (I think they were civilian contractors) would take a stencil and spray paint a red Arkansas Razorback on the two speed brake panels. This was back in the days of the all white T38 paint job. The panels were a little bit aft of the rondel on the bottom of the aircraft. It was something everyone sort of snickered about until half the aircraft had Razorbacks and the wing commander called Little Rock and they finally stopped it. Share your harmless pranks.