corrections legibly in ink, correcting all copies at the same time. Two ink changes are permitted on a  page.  Retype  to  correct  minor  errors  only  in those   few   cases   when   the   importance   of   the subject  or  the  addressee  justifies  the  expense  of retyping. 8. Sign and Mail Promptly. Sign correspond- ence   throughout   the   day   rather   than   just   at the  end  of  the  day.  This  will  keep  signed correspondence  from  lingering  overnight  before it  goes  out. 9. Reply Promptly. Give prompt attention to incoming   correspondence   that   requires   action or answers. Normally, answer correspondence in no  more  than  15  workdays  or  in  the  time  set by  the  incoming  correspondence.  Congressional correspondence  must  be  answered  within 5  workdays  of  receipt. 10.  Limit  Information  Copies.  Include  only those  copy-to  addressees  that  have  a  genuine need  to  know. 11.  Avoid  Unnecessary  File  Copies.  Central- ize  files  whenever  possible  to  eliminate  redundant ones.   See   SECNAVINST   5210.11C   for   more guidance  on  filing. 12.   Reuse   Paper.   Use   salvaged   paper   for written   or   typed   drafts,   computations,   and rough   notes.   Obsolete   forms,   for   example, can  be  cut  into  stacks  of  note  paper. 13.  Update  Distribution  Lists.  Tell  the originator  if  you  continue  to  receive  documents needlessly. 14.  Take  Advantage  of  New  Office  Techno- logy.  OPNAVINST  5210.12A,  Navy  Word  Pro- cessing  Program,  describes  the  main  types  of equipment   and   details   survey   procedures   for determining an activity’s work processing needs. Micrographics   offers   a   reliable,   compact,   and inexpensive  way  to  pass  and  store  informa- tion.  SECNAVINST  5210.12C,   Micrographic Management,   gives  broad  policy  on  obtaining approval  to  buy  micrographic  equipment. 15. Military models of address for all armed services  are  contained  in  Appendix  A,  SEC- NAVINST  5216.5C. 16. Civilian models of address are contained in  Appendix  B,  SECNAVINST  5216.5C. 17.  For  instruction  on  writing  directives  see SECNAVINST    5215.1C. STANDARD  SUBJECT IDENTIFICATION  CODES Use Department of the Navy Standard Subject ldentification   Codes,   SECNAVNST   5210.11C, for   categorizing   and   subject   classifying   Navy and Marine Corps information; identifying direc- tives, blank forms, and reports; and establishing filing and retrieval systems. SECNAVINST   5210.11C   consists   of   three sections: Section 1 Section 2 Section 3 Filing  Procedures Construction  of  Standard  Subject Identification  Codes  (SSIC) List  of  SSIC  Codes MAJOR SUBJECT GROUPS The  Navy’s  SSIC  system  is  broken  down into  13  major  subject  groups: 1000 Series MILITARY PERSONNEL.  In- cludes subjects relating solely to the administra- tion  of  military  personnel.  (Civilian  personnel subjects  are  included  in  the  12000  series.  General personnel   subjects   relating   to   both   civilian and   military   personnel   are   included   in   the 5000 series.) 2000 Series TELECOMMUNICATIONS. In- cludes   subjects   relating   to   general   communi- cation  matters  and  to  communication  systems  and equipment. 3000  Series  OPERATIONS  AND  READI- NESS. Includes subjects relating to such matters as  operational  plans,  fleet  operations,  operational training   and   readiness,   warfare   techniques, operational  intelligence,  research  and  develop- ment,  and  geophysical  and  hydrographic  support. 4000 Series LOGISTICS.  Includes  subjects relating  to  logistical  support  of  the  Navy  and Marine   Corps,   including   procurement,   supply control,   property   redistribution   and   disposal, travel  and  transportation,  maintenance,  construc- tion and conversion, production and mobilization planning,  and  foreign  military  assistance. 5000 Series GENERAL ADMINISTRATION AND   MANAGEMENT.   Includes    subjects relating  to  the  administration,  organization, and management of the Department of the Navy, including general personnel matters (concerning both  military  and  civilian  personnel),  records management  programs,  security,  external  and internal relations, audiovisual management, law and   legal   matters,   office   services,   office automation,  and  publishing  and  printing  matters. 10-22