1. Unless other cipher procedures are especially prescribed, all
secret communications are to be enciphered on the Enigma. The
abbreviated plain text is enciphered directly.
2. If no working Enigma is available, then such radio messages as
should be enciphered per Enigma, General Procedure, are to be en-
cihered according to the Reserve Hand Procedure, General, (R.H.V.
Allg.) - M.Dv. 929/1.
3. General regulations about the Enigma and the Ciphers of the
Day for the Enigma are given in the (Most Secret) publication, "Der
Schluessel M Allgemeine Bestimmungen" ("General Regulations for the
Enigma") - M.Dv. 32/3.
4. For ciphering per Enigma, General Procedure, the following
things are necessary besides the Enigma and all that goes with it:
a) Cipher of the Day for the Enigma, General, (Tagesschluessel
b) K-Book - M Dv. 98 - with cipher procedure and cipher book
for indicator groups.
PREPARATION OF THE PLAIN TEXT
5. The message must be as brief as possible, but nevertheless clearly
The formation of the text is the originating station's affair.
6. In order that the messages attain the brevity necessary for radio
traffic, all abbreviations can be used which are customary in standard
written German and in the Navy. Final syllables and single letters
can in many cases be omitted without damage to intelligibility, and
the umlauted letters, a, o, and u can in general be represented by
A, O, and U. The letter C is to be used instead of CH. Periods
after abbreviations can be omitted whenever such an omission does
not impair intelligibility.
7. All systematic and uniformly applied abbreviation of words is,
however, to be avoided. For example, it would be wrong always to
abbreviate "Funkspruch" by "Fkspr.", because such regularities are
an aid to unauthorized deciphering. However, the most important
principle is that the sense of the message must be clear and unmis-
takable to the receiver. Before being enciphered, every message is
to be checked in this regard.
A varying treatment of abbreviation renders unauthorized de-