to  help  you  remember  the  proper  usage  of  each word. PRINCIPAL  means  MAIN  or  the  main  one — — The  principal  of  the  school Payment  of  principal  and  interest The principals in the play have the main roles The principal objections to the plan are. . . PRINCIP  LE  means RU LE or theory The  principles  of  democracy We  understand  it  in  principle In choosing between princip al and principle, remember—if the word main could be substituted for  principal,  then  principal  is  the  correct  word. If  the  word  r u le   could   be   substituted   for principle,   then  principle  is  the  correct  word. This  pattern  may  not  be  true  in  every  instance, but it is a good way to remember the difference. From  words  that  are  related  or  similar  in meaning, the discriminating writer will select the one that best suits the purpose of the letter. The words  obtain,  procure,  and  secure  can  serve  as an  example.  Obtain  is  the  more  general  term. Procure  has,  in  the  Navy,  a  specific  connotation of  obtaining  material  through  official  channels and   by   approved   supply   procedures.   Secure is  often  used  incorrectly  for  obtain  or  procure. Its  specialized  Navy  use,  meaning  to  fasten something  down  or  make  it  firm,  is  the  correct clue to its general meaning. While the words fewer and  less  seem  much  alike  in  meaning,  fewer describes  number,  and  less  describes  quantity “fewer  AWOL  cases”;  “amp drawing less water. ” In  choosing  words,  always  keep  in  mind  the person  for  whom  the  letter  is  intended.  For example,  when  a  letter  to  a  senior  command  is being  prepared,   “Attention  is  invited”  is  used rather  than  “Attention  is  directed”;  and  “it  will be appreciated if.  .  can  be  maintained”  is  used instead  of  ‘‘.  .  shall  be  maintained.  ” A directive addressed to all hands should be written  in  language  all  can  understand.  This means that the words chosen must be meaningful to   all   hands.   The   following   sentence   is   an example   of   a   simple   idea   stated   in   a   very complicated manner:  “Having  cognizance  of  our rigid operating schedule, the commanding officer, in   an   attempt   to   ameliorate   morale,   is   en- deavoring  to  ascertain  the  proclivities  of  those personnel  who  are  encountering  difficulty.  .  .” The  following  sentence  is  the  same  idea stated   more   simply: “Being   aware   of   our strict  operating  schedule,  the  commanding officer,  in  an  attempt  to  boost  morale,  is  trying to   determine   the   nature   of   those   difficulties personnel   are   encountering.” Paragraph Organization A  well-written  paragraph  has  unity,  which means that the ideas it contains are closely related and  are  arranged  so  that  they  develop  a  single topic   or   subtopic   of   the   general   subject.   In modern  official  letter  writing,  the  tendency  is toward  short  paragraphs  for  the  sake  of  read- ability. This requires not only that all unnecessary verbiage be pared away, but also that the subject matter  be  carefully  organized  and  subdivided. THE  TOPIC  SENTENCE.—  A  fairly  long paragraph  is  frequently  made  more  effective  if introduced by a topic sentence. Such a sentence makes  a  general  statement  that  is  developed  in greater detail in the remainder of the paragraph. A topic sentence need not stand at the beginning of a paragraph;  in  fact,  it  is  possible  to  have  a  well- written  paragraph  with  a  topic  sentence  in  the middle  or  at  the  end.  In  naval  correspondence,  the topic  sentence  is  less  likely  to  be  placed  in  the middle of the paragraph. If placed at the end, it becomes  a  summary—a  very  useful  device  for pulling  the  paragraph  together  and  leaving  a  strong final  effect.  However,  the  topic  sentence  at  the end of a paragraph is not used extensively in naval letters and directives. A summary paragraph for an entire letter is sometimes appropriate. ORDER   OF   SENTENCES.—   A  well- organized  paragraph  has  its  various  ideas introduced in an orderly sequence. This sequence may  be  place  order,  chronological  order,  logical order,  or  order  for  emphasis.  All  four  have  the same   purpose—to  lead  the  reader  along  the desired path with a minimum of backtracking or skipping  about,  and  thereby  leave  the  reader  with a  clear,  strong  impression  of  what  the  writer  is trying  to  convey. PLACE ORDER is used for descriptions. The following description was taken from the report of  a  shipboard  accident. During preparation for the transfer of fuel,  seven  sections  of  2  1/2-inch  hose  were connected   and   rigged   between   a   Navy cargo ship and a fuel oil barge. The hose passed through a hold of the ship in which there were several light fixtures of the type designed   for   use   with   globes   and 3-12