SUPPLY   OVERHAUL—The   physical   effort involved   in   purifying   and   adjusting   onboard stocks and records to bring them into agreement with   the   prescribed   allowances,   thereby improving  the  supply  readiness  of  the  ship. SUPPLY  SOURCE  CODE—Identifies  the  basis  or means of material availability at the time an item is  requested.  It  is  a  code  that  identifies  previously issued  material  that  is  returned  to  the  supply department  in  ready  for  issue  (RFI)  condition. The supply source codes to be used are found in the NAVSUP P-485. SUPPLY   SUPPORT—The   materials   and   services that  are  necessary  for  the  operation  of  the  ship  and which  are  obtained  from  ashore  activities  or  other ships. SUPPLY   SUPPORT   CENTER—A   single   point   of contact between the supply department and the ship’s   other   departments   to   provide   material identification,  requisition  status,  and  stock  status information. SURVEY—The  procedure  used  to  expend  material from   stock   records   and   accounts   when   it   is deteriorated,  damaged,  lost,  missing,  or  otherwise unavailable  for  its  intended  use. TARE  WEIGHT—The  weight  of  the  container  and the material used for packing. TCN   FOR   SHIPMENT   UNITS   IN   CONSOLIDA- TION—The  TCN  assigned  to  control  shipment units  in  consolidation  is  the  TCN  of  the  shipment unit having the earliest RDD, or earliest TCN date. T R A N S P O R T A T I O N     A C C O U N T     C O D E S (TACs)—Four-position alphanumeric codes that identify   the   shipment   of   material   to   Navy operations and maintenance funds, procurement funds,  and  other  Navy  funds  which  ultimately reimburse   the   Navy   Management   Fund   for shipment  charges.  They  must  be  shown  on  all government  bills  of  lading  (GBLs),  transportation control and movement documents (TCMDs), and other   transportation   documents   that   incur obligations  against  the  Navy  Management  Fund. To  find  a  TAC  number,  to  MILSTAMP  DOD Regulation 4500.32R, Volume II. TRANSPORTATION    CONTROL    NUMBERS (TCNs)—The  basic  element  of  the  MILSTAMP system. A number is assigned to each shipment unit   as   the   shipment   control   from   origin   to destination. TRANSPORTATION    OFFICERS—Officers    that act as agents for the government in the execution of contracts of carriage between carriers and the government.  They  initiate  and  receive  shipments of property for which the government pays the transportation  charges  or  in  which  the  government has an interest. TRANSFER—An   action   that   shifts   custody   and responsibility  for  material  from  one  supply  officer to  another  supply  officer  or  another  activity. TRUST  FUND—A  fund  into  which  are  deposited receipts  that  are  held  in  trust  in  accordance  with an   agreement   or   legislative   act   and   may   be expended  only  in  accordance  with  the  terms  of such trust or act. UNIT   IDENTIFICATION   CODE—A   symbol assigned by the Comptroller of the Navy to ships, aircraft units, stations, and other activities or units for  purposes  of  identification  on  all  accounting documents  and  reports. UNIT LOAD—Assembling of packages or items into a  single  load,  within  a  container,  van,  or  palletized so it can be moved unbroken from the source to the user. UNITIZED  LOAD—A  single  item,  or  a  number  of items packaged, packed, or arranged in such a way that it can be handled as a single unit. Unitization may be accomplished by placing the item or items in  a  container,  or  by  banding  them  securely together. UNIT PACKAGE—The first tie, wrap, or container applied to a single item or a quantity, or to a group of items of a single stock number, that constitutes a  complete  or  identifiable  package. USAGE  DATA—Past  experience  figures  showing  the rate of issue for specific items of stock. VALIDATION,   EQUIPMENT—See   equipment validation. AI-10