In the early 70's in Germany on a NATO exercise we were dug in with the Tanks doing a 24 hour Radio silence routine. A real pain in the Butt.
After about 8 hours came a voice; "I'm Pissed Off". Then nothing.
2 hours later, "I'm Pissed Off". Nothing.
2 hours later, "I'm Pissed Off". Nothing.
2 hours later, "I'm Pissed Off". Some officer's voice, "Hello unnamed call sign. Identify, Over".
"I'm not that Pissed Off".