If you happen to indulge in reading about WW II and the many 'war-tools' that was introduced by Japan & Germany, this article maybe of interest to you.
Along about September of 1943 the Allies couldn't quite wrap their minds around "why" there was a sudden rise in warship losses
Well there was a new "tool" that the enemy was not putting on the neon war billboard.
They (the enemy) was saying silently to whomever....we are introducing you to
FRITZ X
If you care to give this a going over, I think you'll find it most interesting.
