and  exempted  addressees.  Plain  language  address is the pharse used to denote the format and ordinary  language  spelling  of  command  short titles  and  geographical  locations  used  in  message addresses.  The  NTP  3  SUPP-1(K)  and the  United States  Military  Communications  Electronic  Board (USMCEB)  publication  list  the  authorized  plain language  addresses  for  naval  messages. The  FROM,  TO,  INFO  lines  of  a  naval message  contain  plain  language  addresses. Messages must have only one originator address but  may  have  unlimited  action  and  information addressees. Some  messages  may  be  addressed  to  activities listed  under  collective  address  designators  (CADs) or  address  indicating  groups  (AIGs).  Only authorized  activities  may  originate  these  multiple- address  messages.  However,  personnel  responsible for  determining  whether  action  is  required  on incoming  message  must  know  which  CADs  and AIGs include their command. Collective Address Designator. —Collective address  designators  are  single-address,  alphabeti- cally sorted, common-interest groups. Each CAD represents  a  predetermined  set  of  activities  linked by an operational or administrative chain of command.  Some  examples  of  CADs  are  NAV- FOREUR,  NAVFORJAPAN,  and  CRUDES- FORSEVENTHFLT. Address Indicating Group.  —Address   indi- cating  groups  represent  predetermined  lists  of specific and frequently recurring combinations of action and information addressees or both. AIGs are  identifed  by  numbers  that  expedite  message processing  in  both  administrative  and  tele- communications  channels  and  may  pertain  to  the following: Alerts,   air   defense   warnings,   and operational  or  emergency  actions Severe  weather  or  destructive  storm warnings Logistical  transactions  or  reports Movement   reports TEXT COMPONENTS.  —The text com- ponents of a message consist of the classification line,  passing  instructions  line,  subject  line, reference  line,  and  the  basic  text  or  message. Classification  line.  —The  classification  line  of the security classification and the standard subject identification  code  (SSIC).  When  applicable,  the line  also  includes  special-handling  markings.  The security   classification   or   the   designation UNCLAS, for unclassified information, must appear  on  all  messages. Certain  types  of  messages  require  special- handling in addition to that provided by the security  classification.  Markings  that  indicate special-handling requirements (for example, SPECAT,   LIMDIS,   PERSONAL   FOR)   are placed in the classification line immediately following  the  security  classification.  NTP  3(H) contains  specific  instructions  concerning  special- handling  markings. The  standard  subject  identification  code  is  the last element of the classification line. It is required on all Navy-orginated messages, except as noted in NTP 3(H). The SSIC is used as one method for  the  determination  of  internal  message distribution. Be careful to select the SSIC that most completely and accurately corresponds to the  message  subject  matter. Passing Instructions Line.  —Passing  instruc- tions,  when  applicable,  are  located  on  the  line below  the  classification  line.  Passing  instructions consist  of  office  codes,  symbols,  or  names. However, passing instructions may be used on naval  messages  only  as  authorized  by  NTP 3(H). Subject Line.  —The subject line begins on the  line  following  the  classification  line  or  the passing  instruction  line  when  it  is  used.  Message subject lines indicate to the reader the basic contents of the messages text. You may omit the subject  line  for  tactical  messages  when  the following  occurs: 1. 2. 3. It  will  cause  otherwise  unclassified  message to  be  classified. It will noticeably increase the length of a short   message. The  subject  is  readily  apparent  in  the  first line of the text. Reference  Line.  —Reference lines are used as alternatives  to  the  repeating  of  lengthy  references within the text of the message. You may use any identifiable   document,   all   messages,   and telephone conversations in a message as long as the  reference  line  is  clear  and  specific.  Letter  each reference   consecutively. 2-35