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On 1.1.42 the Flottenkurzsignalheft and U Bootskurzsignalheft were withdrawn and replaced by Kurzsignalheft 1941 (C) which was issued to U-Boats and Fleet units alike.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.
| Cypher | Decode | Meaning | ||
| B'B' | ||||
| Indic. | OOD | Setting | VEF | |
| T.O.O. | 1732/26 | |||
| Text | QLTI | CKSA | Convoy |
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