When I was in the Navy, we used rolls of carbon paper sandwiched between regular paper. When we got a new sailor, someone ripped the layer of regular paper off the outside of the roll so the outside layer was the carbon paper. He told her that the roll was defective and that to fix it, she would need to unroll all the paper and reroll it with the layer of carbon paper in between the regular paper layers.
The whole time she was unrolling the paper, she kept muttering, “It’s a mail buoy trick. I just know it.”
Finally, the prankster took the roll, ripped off the 20 or so feet she had unrolled, then tore off the outer layers of paper so that the roll was once more layered in the paper-carbon-paper configuration. At that point, the new sailor yelled, “I KNEW it was a mail buoy!”
What’s a mail buoy?