There were no other differences between B's and Short E's, and B's also were used for obtaining Augsburg settings.
d) B-Bars (Kurzsignale) January 1942 onwards.
On 1.1.42 the Flottenkurzsignalheft and U Bootskurzsignalheft were withdrawn and replaced by Kurzsignalheft 1941 (C) which was issued to U-Boats and Fleet units alike. This code book was an enlargement of Feodor with new 4 letter groups to cover (a) the complete Naval Grid and (b) all special U-Boat requirements. No other Short Signal book was necessary. In practice the book was used almost exclusively by U-Boats, the most frequently used parts of the 120 page book being:
|Part||3||Enemy Reports||Groups beginning with||C.|
|9||Rendezvous||" " "||F.|
|14||Grid Squares||" " "||J, K, P.|
|16||Numbers||" " "||M, N.|
|18||Dates||" " "||P.|
|19||Time of day||" " "||P.|
|20||Course Indication||" " "||Q.|
|21||Speed Indications||" " "||Q.|
|24||Homing Reports, Beacons||" " "||U.|
|27||Groups for Dummy Signals||" " "||W.|
In spite of the length of the book, the alphabetical arrangement of groups and the orderly arrangement of phrases made an inverse book unnecessary.
With Kurzsignalheft 1941 was issued Kenngruppenheft Nr. 1 zum Kurzsignalheft 1941 (I) -- an indicator book containing 310 numbered indicator trigrams with the equivalent message settings e.g.
161 EWB gives setting DOV
162 RAS " " ZBS
The numbers acted as discriminants, different blocks of numbers being allotted to particular keys (according to the day of the month). All indicator trigrams in Kenngruppenheft Nr. 1 obeyed the rule a+b = c (mod 25). The letter I never occurred and was left out of the alphabet.
Kenngruppenhefts 1, 2, 5 and 6 were brought into force successively, number 6 having 400 instead of 310 indicators.
The following example shows a typical B' of the period.