A captured Italian Intelligence Report states that in
communications during field operations the British have
made "abundant use of abbreviations, conventional
words, names, and agreed phrases." The Italians admit
that these methods have proved effective. "In particular," the
report says, "key words for deciphering messages
giving fresh positions have been well thought out. It has
been observed that, by way of a change from past practice, two
different codes have been used in a single message, one
code in numbers and the other in words. For example,
'Position of Pura is Jsy. A5N.' Such messages take our
cipher expert so long to unravel that the information they
contain is useless to us."
This is good news—for our side. Nevertheless, from
the same source the American soldier can pick up a few
tips about how not to send radio messages in the field. The
British used to rely heavily on frequent changes of
names, frequencies, and key words or numbers. Instead
of confusing Axis listeners, this kind of thing tended to
make them more alert. The British soon learned that
instead of changing codes frequently, it was better to
change them cleverly. For example, certain units, whose
code names had been changed had been including references
to earlier messages transmitted under their former
names; these references specifically mentioned the old
names and dates. In these cases identification of the
unit by the Axis was a simple matter. Also, apparently
unimportant messages helped in identifying certain
infantry battalions about which the Axis had very little
information.
It is interesting and useful to know what communication
methods make field operations easier for the enemy
and what methods make them more difficult. The captured
Italian report reveals that the British often have
puzzled the enemy by using cockeyed slang and
double-talk. It must be stressed, however, that this method does
not guarantee safety. For example, the American expression
"Keep your shirt on" might mean nothing to the
enemy, but on the other hand it might mean a great deal—because
the Axis armies include many men who have
lived in the United States.