The repeating of the message is how the Allies initially broke the Geheimskreiber a much more secure encryption machine to Enigma that used XOR and rotors:

https://en.wikipedia.org/wiki/Siemens_and_Halske_T52

This is interesting in itself because should the Germans have got a hold of this widespread memo, then it might have tipped them off as to how their Enigma system might be attacked.