communication instructions radio telegraph procedure

UNCLASSIFIED ACP124 (D)
203. SERIAL NUMBER
The Serial Number is a number allocated by stations to identify a message. In certain
circumstances it is used as transmission identity.
204. TRANSMISSION IDENTITY (PROSIGN NR)
a. Transmission identification may be employed to provide a means of assisting the
receiving station in ascertaining that it has received all messages sent to it by a particular transmitting
station. When messages are transmitted by broadcast method, the call sign of the transmitting station or
the broadcast identifying letter and figures (the broadcast designator) is also used. The prosign NR is not
normally used in connection with broadcast designators.
EXAMPLE 1: (Station to Station)
NPQR DE GABB NR172 – etc.
EXAMPLE 2: (Broadcast)
NAWS DE GYE X42N O69 – etc.
b. In a multiple call the station serial number applicable to each called station is given in
the same sequence as the call signs in the call.
EXAMPLE:
NPQT NPQR DE GABB
NR148 – NR371 – etc.
205. TRANSMISSION INSTRUCTIONS
Transmission instructions concern the actual transmission of a message and are appended by
communications personnel. They include the prosigns G,F and T, and the operating signal ZWL,
described in the following paragraphs.
206. PROSIGN G (REPEAT BACK)
a. The prosign G, meaning "REPEAT BACK THE ENTIRE TRANSMISSION", is used by
the transmitting station to ensure that the receiving station received the message as transmitted. It may be
ordered by either the originator or the circuit operator and may apply to the station called, all stations
called, or stations designated before the prosign G in the transmission instructions. The instruction to
repeat back applies to the whole TRANSMISSION.
EXAMPLE 1: (Station called to repeat back.)
M9VO DE NPQR
-G_
BT
TEXT
BT
1415Z
K
M9VO complies as follows:
UNCLASSIFIED 2-2