A guy brought his gun into the local shop with a CP reg that "didn't work." The air line was run into the guage port.
Some kid that was adjusting "the loudness knob" on his timmy before it started leaking in between the grip and body. After reattaching the hose I ended up using a sharpie to write "max loudness" on the LPR guage. The shop owner wiped it off before giving it back to him.