When a message exceeds five textual pages, the message must be divided into transmission sections. The message should be separated at a convenient point on the last permissible page of a transmission section. This normally will be at the end of a sentence or cryptopart.  Each  section  must  be  numbered  in  plain language  at  the  beginning  of  the  text  following  the classification   or   abbreviation   “UNCLAS.”   For example: UNCLAS SECTION 1 OF 2 In long encrypted messages, when a transmission section starts with a new cryptopart, the designation of the  cryptopart  follows  the  designation  of  the transmission  section.  Also,  when  a  numerical  group count is associated with an off-line encrypted message and is indicated in format line 10, the count must indicate the number of groups in the textual section being transmitted— not the number in the complete message.  Cryptopart  identification is included in the group count; the  page identification and transmission section  are  not. Statistical  and  meteorological  messages  can  have up  to  100  lines  of  text  without  paging  when  the inclusion   of   paging   information   would   disrupt processing by the user. However, you should divide these types of messages into transmission sections if they exceed 100 lines of text. Misrouted and Missent Messages A  misrouted  message  is  one  that  contains  an incorrect routing instruction. This normally occurs when  the  originating  communications  center  assigns  an incorrect routing indicator during message header preparation.  Misrouted  messages  are  usually  not discovered until they reach the communications center of  the  called  routing  indicator.  Communications personnel of a tributary station in receipt of a misrouted message must take the following actions: Obtain the correct routing indicator, if possible; Apply a header change to the misrouted message and  retransmit  it  to  the  correct  routing  indicator; and Originate a service message to the originating station  advising  of  the  reroute  action  and  the correct  routing  indicator. A missent message is one that contains a correct routing indicator but is transmitted to a station other than the one represented by the routing indicator. Missent messages can be caused by an equipment malfunction,  incorrect  switching,  or  operator  error. Communications  personnel  of  a  tributary  station  in receipt of a missent message must take the following actions: Reintroduce  the  message  into  the  AUTODIN system  as  a  suspected  duplicate  (SUSDUPE) after applying a header change; and Forward  a  routine  service  message  to  the connected ASC citing the complete header and time of receipt (TOR) and advising that the message has been protected. Suspected Duplicates When a station suspects that a message may have been previously transmitted, but definite proof or prior transmission  cannot  be  determined,  the  message  should be forwarded as a suspected duplicate (SUSDUPE) by applying  a  header  change.  However,  if  a  station receives   a   message   that   is   already   marked “SUSDUPE,” the station should file the message if the message was previously received and delivered to the addressee. If there is no indication that the message was previously  received  and  delivered,  it  should  be forwarded. Stations   receiving   unmarked   duplicate transmissions  should  immediately  forward  a  routine service message to the originating station. This service message should cite the complete header format of the duplicated message, including the TOR of the original and  duplicate  transmissions.  If  the  initial  copy  was delivered to the addressee, the station should file the message. Upon  receipt  of  service  messages  concerning duplicates,   communications   personnel   at   the originating station must take the following actions: Check  transmission  records  to  determine  the validity of the duplication report; Ensure  that  in-station  procedures  are  adequate  to guide operating personnel in the retransmission of SUSDUPE messages; Have    maintenance    personnel    perform equipment checks if an equipment malfunction is suspected to be the cause of duplication; and 1-10