barmar, on 2014-January-27, 19:23, said:
All these threads about dummy and/or opponents mishearing declarer's designations remind me of how they addressed this in a different, more critical field of endeavor. If you've ever wondered by airplane pilots and control towers say "niner" instead of "nine", it's because the latter sounds just like the German word "nein".
It is also why the number 5 is omitted from countdowns in the army (et al), since this could be mistaken for the word "Fire!" with unpleasant consequences.