to the order of message divisions according to content. The
separate message divisions can also be sent in any succession.
38. The whole message -- unless radio operational necessities
dictate otherwise -- is always to be designated only by the time
group of the message division which is first in order according to
39. On the final copy of such a message received, the time group
of the first message division is to be especially marked; the
separate message divisions are to be put together in consecutive
orden to make up the whole message, and the points of division are
not to be emphasized. The contents of the message may of course
necessitate a subdivision into outline or paragraph form in its
41. The indicator groups needed to indicate the Enigma as the
ciphering device end the General Procedure as the procedure to be
used the indicator group procedure, and the "Cipher Book for
Indicator Groups" ("Schluesselheft fuer Kenngruppen") are all con-
tained in the K-Book -- M.Dv. 98.
42. Every message is given two different indicator groups from the
K-Book, of which.
The first serves as cipher indicator group to indicate
use of the Enigma as the cipher device, and to indicate further the
use of the Cipher of the Day for Home Waters or for Non-home Waters
or for Special Ship Cipher,
The second serves as procedure indicator group to indicate
the General Procedure and to form the Message Cipher (Spruchschluessel).
43. It is of the utmost consequence for cipher security that
different indicator groups are used for every message.
Book Indicator Groups.
44. The two three-letter indicator groups taken from the K-Book
are called Book Indicator Groups. The first thing that happens to
them is that they get written in unchanged, in the column entitled
"Book Groups" (Buchgruppen), in the following manner:
The Cipher Indicator Group as first Book Group, and.
The Procedure Indicator Group as second Book Group.