When I first enlisted in the Corps in 1993, we were shipped to San Diego Recruit Depot. After the first night's sleep of two hours, we were wakened at oh-dark-hundred and did the basic indoctrination, head shaved, how to speak, take orders, formations and drill, then the wonders of Hydration™. Everyone had to drink two canteens of water, and then we drilled again. We then went back to the receiving barracks for our urinalysis. This was three hours later after drinking so much water that everyone was in agony.
Then came the security instructions, put red tape across lid then put initials across tape to sort of secure the container against tampering.
Well the receiving Jr. DI used a quick demonstration of the first three letters of the alphabet "ABC" then said to use our own "initials."
Well, we filled the cups. Standing in line waiting for our containers to be inspected and down the line he went. When he saw mine it had "ABC" across the top as instructed, boy did he blow a gasket! You know—the kind when the veins in their forehead pulse.
He then asked what my name and initials were and I told the junior drill instructor, he had this look of confusion and embarrassment then stormed out of the barracks and everyone burst out in laughter including the senior DIs in the duty hut who interrogated me later about the event with a kind of smirk and hidden laughter.
Semper Fi!