Functional  title By  direction  of  the  (senior  official’s title),  if  appropriate REFERENCES   AND   ENCLOSURES The  business  letter  does  not  provide  for  a Reference   block. Any references   are mentioned  in  the  text  only.  Enclosures are both  mentioned  in  the  text  and  then  described briefly  in  an  Enclosure  block.  Type  Encl:  at the  left  margin  on  the  second  line  below  the Signature block and list the enclosures beneath the  heading.  The  rules  for  marking  special distribution  of  enclosures  are  the  same  as  in  a standard   letter. COPY  TO  BLOCK If   everyone   should   know   that   a   particular addressee  will  receive  an  information  copy, show  that  addressee  in  the  Copy  to  block. Use   long   titles   for   activities   listed   in   the SNDL.  Type  the  words  Copy  to  with  a  colon at  the  left  margin  on  the  second  line  below the  previous  block  (Enclosure  block,  if  any,  or the  Signature  block).  Addressees  are  listed beginning  on  the  next  line  at  the  left  margin. MESSAGES This  portion  of  the  chapter  will  introduce  you to   basic   message   traffic   format   (MTF). Although  there  are  many  types  and  modes  of communications, the basic naval message must conform   to   a   standard   format   with   few exceptions.  As  a  YN,  you  need  to  be  familiar with  all  of  them. COMMON   MESSAGE   ELEMENTS Before  covering  the  basic  format  of  military messages,   we   will   first   discuss   the   time system, precedence categories, and speed-of-service   objectives   used   in   naval communications. Time Time   is   one   of   the   most   important elements   in   communications.   Messages   are normally  identified  and  filed  by  either  a  DTG or  a  Julian  date,  depending  on  the  method  of transmission. Date-Time-Group The  DTG  is  assigned  for  identification  and file   purposes   only.   The   DTG   consists   of   six digits.  The  first  two  digits  represent  the  date, the  second  two  digits  represent  the  hour,  and the third two digits represent the minutes. For example,   221327Z   AUG   94   means   the   22nd day  of  August  plus  the  time  in  Greenwich mean  time  (GMT).  The  dates  from  the  first  to the ninth of the month are preceded by a zero. This   designation   is   followed   by   a   zone suffix  and  the  month  and  year.  The  month  is expressed by its first three letters and the year, by  the  last  two  digits  of  year  of  origin;  for example,   081050Z   AUG   94.   The   zone   suffix ZULU  (Z),  for  GMT,  is  used  as  the  universal time  for  all  messages. Greenwich  Mean  Time In   naval   communications,   the   DTG   is computed f r o m    a    c o m m o n    w o r l d w i de standard.  To  meet  the  need  for  worldwide time   standardization,   the   international   GMT system  was  developed.  The  GMT  system  uses a  24-hour  clock  instead  of  the  two  12-hour cycles  used  in  the  normal  civilian  world. Julian  Date The   Julian   date   consists   of   three   digits. They  represent  the  day  of  the  year.  The  first day  of  the  calendar  year  is  Julian  001,  and each day is numbered consecutively thereafter. For   example,   in   Julian   0311315,   031   is   the 31st  day  of  the  calendar  year  (January  31). 3-22