(JANAP 128), content indicator code (CIC) (JANAP 128), originating station routing indicator (OSRI), station serial number (SSN), and time of file (TOF) to the message. The message is then paged and sectioned according  to  JANAP  128,  and  queued  for  transmission. Data-pattern messages may be introduced into the system via card or magnetic tape. The format will be in  accordance  with  JANAP  128  procedures  for  data messages. During the message preparation, processing, transmission,  and  filing,  the  same  controls  and restraints used for narrative message processing will also apply to data-pattern messages. The message may also have delivery requirements for   distribution   to   commands   serviced   by   the communications center. The system will automatically assign  internal  message  distribution  for  all  guard commands.  If  the  system  cannot  provide  internal distribution, the message will be displayed to the inrouter for assistance. MESSAGE AND ROUTING ADDRESSEES Most  messages  have  at  least  one  addressee responsible for taking action on the contents and for originating any necessary reply. Addressees who have an official concern in the subject of the message, but who do not have primary responsibility for acting on it, receive   the   message   for   information.   Although information addressees are usually concerned only indirectly with a message, they occasionally must take action  of  some  kind  within  their  own  commands.  Some messages contain only information addressees. Messages may be divided into types, according to the way they are addressed, as follows: Single-Address—  A message that has only one addressee,   which   may   be   either   for   action   or information. Multiple-Address—  A message that has two or more  addressees,  which  may  be  either  action  or information  and  where  each  addressee  is  informed  of all  other  recipients. Book—  A message destined for two or more addressees  but  where  the  drafter  considers  it unnecessary that each addressee be informed of other addressee(s). Book messages are routed according to each   addressee’s   relay   station.   All   unnessary addressees are deleted from the face of the message before  being  sent  to  the  addressee(s)  served  by  that particular relay station. General Message—  A message that has a wide, predetermined,   standard   distribution.   General messages are normally titled with a sequential number for the current year; for example, ALCOM 28/96, NAVOP 30/96. The title indicates distribution and serves  as  the  address  designator. ADDRESS GROUPS Address groups are four-letter groups assigned to represent a command, activity, or unit. In military communications,  address  groups  can  be  used  in  the same manner as call signs to establish and maintain communications. Generally speaking, the Navy uses address groups the same way as call signs. Address groups never start with the letter N; hence, they are easily distinguishable from naval radio call signs. Address  groups,  however,  follow  no  distinctive  pattern, and the arrangement of the four letters that constitute them conveys no significance whatsoever. Afloat  commands  (except  individual  ships)  and shore-based  commands  or  activities  not  served  by  their own  communications  facilities  are  assigned  address groups. For example: l l l Senior  commands  and  commanders  ashore,  such as the Secretary of Defense and the Secretary of the  Navy; Navy bureaus, systems commands, and district commandants; and Elements of the shore establishment having a need for direct addressing and receipt of message traffic (such as weather centrals). Among  other  uses,  address  groups  facilitate delivery of message traffic when a communications center serves so many activities that its own call sign is insufficient to identify the addressee. Address groups are contained in  Allied Call Sign and Address Group System—Instructions and Assignments,  ACP 100, and in U.S. Call Sign &Address Group System Instructions & Assignments (U.S. Supplement No. 1),  ACP 100 U.S. SUPP-1. Like call signs, address groups are divided into  the  following  types: l Individual activity; l  Collective; l  Conjunctive; l  Geographic; l Address indicating; and 2-17