Luftwaffe in Birmingham area on 11 December 1940

[Nick Beale]

Originally Posted by Dan History

Nick, the codenames reported by ULTRA are most interesting. I did not expect that the surnames of Nazi leaders would have been used.

Those are British substitutions for the original German codenames which were all major rivers. The change was made to avoid giving the Germans a "crib" to break into British codes. The instruction for this was issued on 19 November:

CX/JQ/463
NAVIGATIONAL BEAMS
IMPORTANT NOTICE

2. As from 0001/20/11/40 source CX/JQ will not refer to river type beams by their original names, but will use the following code-words:
WESER = HITLER
SPREE = GOERING
RHEIN = RIBBENTROP
ELBE = HIMMLER
DONAU = QUISLING
ODER = SCHIRACH
ISAR = HESS

What had been known colloquially as "river beams" now became "Ruffians".

May I ask whether this is from HW 5?

TNA HW 5/7.