In 1940 the Lauf and Treuenbrietzen stations that intercepted foreign radio traffic for the German High Command’s decryption department - OKW/Chi, were ordered to give special attention to Greek radio traffic.
The report of 19 January 1940 says:
‘Because of the geographical dispersion of the Greek state in a large number of islands separated from each other by long distances there has been for some time an internal Greek wireless traffic, above all between the mainland and individual islands (e.g. Crete) and probably between island and island also.’
Then a list of Greek radio stations follows.