I had a coworker, an accountant, who did some side work for a government contract. The joke in government accounting circles is that they wish they could pocket the “rounding errors,” as all the figures are in millions.
My exhusband ran a military budget and there were “black programs” in his budget that he was not allowed to even talk about, much less discuss the finances of. One notable one was a study of the flow rate of ketchup. Military secret.