An allowance shall be made in the assessment of duties for deficiencies in the contents of packages when, before the liquidation of the entry becomes final, the importer files:
(a) In the case of a concealed shortage, a Customs Form 5931, in triplicate, executed by the importer alone, and the Center director is satisfied as to the validity of the claim; or,
(b) In the case of an unconcealed shortage, a Customs Form 5931, in triplicate, executed by both the importer and the importing or bonded carrier, as appropriate.
[T.D. 72-258, 37 FR 20171, Sept. 27, 1972, as amended by CBP Dec. No. 16-26, 81 FR 93023, Dec. 20, 2016 ]