ABSTRACT
The interception and study of signals in plain language relies not only on the conversations themselves but also on careless operator chat before and after transmissions. These can help to identify units, both by overt descriptions and by such subtler methods as TINA, the recognition of individual radio-operators, and the identification of different types of radio set by RFP. This information in turn can pinpoint the move of a unit from one area to another, which may well betray a significant feature of the enemy's plans. If operator X, with his idiosyncratic 'fist' (or 'signature' or 'handwriting') was originally in the LEMUR signals net and has now turned up in LEOPARD, what can that tell us about units common to both nets? The answer will suggest how one further piece should fit into the jigsaw puzzle of the enemy's order-of-battle.
