Art, aye, they didn't half pick 'em.
In one exercise they issued ONE envelope to the first crew with instructions that the rest of us were to log what we heard:
The scramble duly came and we all recorded APPLECART. At the debrief was we were shown the code word. At least the first two letters were the same:
APOCATHARY.
And an airborne authentication which we also received properly in morse:
BANDOLARO.
At least NOURISHMENT just before lunch was clearly understood. They switched to alphanumerics a bit later.