Overtime <CR>
This wasn't me, I remember reading it when I was a young whipper-snapper. I think it was in either Practical Computing or PCW in the UK.
The journo had a friend (apocryphal?) who had worked on a large system in the 70s. It was fairly advanced and used an early teletype terminal. He would have to wait for the users to finish for the day, then he could start the reconciliation jobs. He would have to let them run, before powering down the computer and going home...
Only the jobs took hours to complete, which meant missing Corrie or valuable drinking time.
Being a primitive teletype with a roller and moving carriage, the BOFH candidate became creative. A line feed would execute a command, while CR/LF would execute the command and return the carriage to the start of the line... Being sneaky, he batched up all of the commands in the input buffer, then attached one end of a piece of string to the carriage and the other to the power switch of the computer (a throw switch, not a push button).
Thus the jobs would all run sequentially, the carriage would gradually move to its full extent and once the final job had run, it did a shutdown and when that sent the session termination string, the teletype would throw a carriage return, yanking the power switch of the computer to the off position in the process. Obviously, there were a few flaws with this, a spelling mistake in the type-ahead buffer would leave jobs un-run and failed jobs would be ignored...
But, hey, extra beer time whilst being paid overtime for running the jobs - the log showed when "he " shut down the machine, so they "knew" when he had left the building...