[Bruce Dennis]

Originally Posted by Jagdkommando

... But I also find it strange that the brits' would use the same term as the germans, "ESN"- Erkennungs Signale 4.

Or did the brits' used their own term, that ended up with the same letters ??

Very strange indeed. To use the description in an ORB pretty much confirms that it was in common use (not secret, clearly understood by all parties concerned) and relevant. I am intrigued by the thought that the Allied pilots, staff officers and Intelligence officers were using German terminology to (A) describe their own devices and (B) record encounters with the enemy, which were then used to analyze the success or failure of tactics.

If the entry in the ORB betrays the knowledge that the Allies were aware of the colour and even the name of the Luftwaffe recognition signals, it was a gross breach of security. There must also be an English language answer, or you have stumbled across an abuse of the ULTRA security that has previously gone unrecognised.

Bruce