19 CFR § 146.21 - General requirements.
(a) Systems capability. The operator shall maintain either manual or automated inventory control and recordkeeping systems or combination manual and automated systems capable of:
(1) Accounting for all merchandise, including domestic status merchandise, temporarily deposited, admitted, granted a zone status and/or status change, stored, exhibited, manipulated, manufactured, destroyed, transferred, and/or removed from a zone;
(2) Producing accurate and timely reports and documents as required by this part;
(3) Identifying shortages and overages of merchandise in a zone in sufficient detail to determine the quantity, description, tariff classification, zone status, and value of the missing or excess merchandise;
(5) Providing an audit trail to Customs forms from admission through manipulation, manufacture, destruction or transfer of merchandise from a zone either by zone lot or Customs authorized inventory method.
(b) Procedures manual.
(1) The operator shall provide the port director with an English language copy of its written inventory control and recordkeeping systems procedures manual in accordance with the requirements of this part.
(3) The operator may authorize a zone user to maintain its individual inventory control and recordkeeping system and procedures manual. The operator shall furnish a copy of the zone user's procedures manual, including any subsequent changes, to the port director. However, the operator will remain responsible to Customs and liable under its bond for supervision, defects in, or failures of a system.
(4) The operator's procedures manual and subsequent changes will be furnished to the port director for information purposes only. Customs receipt of a manual does not indicate approval or rejection of a system.