This moniker on the atomic bombs in Thunderball may be humorous, but it’s apparently rooted in real-world terminology. The phrase has been used in avionics, including by the Royal Air Force, as a straightforward directive to emphasize extreme care in handling sensitive or hazardous equipment. While the wording may sound almost flippant in such a high-stakes context, its simplicity reinforces a safety mindset. In that sense, the warning works both as a bit of dry wit and as an authentic reflection of operational care.