19 CFR 12.100: Importations in good faith; common or contract carriage.

(a) Exportation in lieu of seizure. Upon a claim that the importer acted in good faith without knowledge of applicable laws and regulations, Customs officers may authorize detained inadmissible knives to be exported otherwise than in the mails, at no expense to the Government, under the procedures of §§ 18.25 through 18.27 of this chapter.

(b) Common or contract carriers. In accordance with 15 U.S.C. 1244(1), excepted from the penalties of the Act are the shipping, transporting, or delivering for shipment in interstate commerce, in the ordinary course of business of common or contract carriage, of any switchblade knife. However, imported switchblade knives as defined in § 12.95(a) so shipped or transported to a port of entry or place of Customs examination are prohibited importations subject to §§ 12.95-12.103 and disposition as therein required, authorized, or permitted.