19 CFR 145.5 : Customs Duties (§ 0.1 To Parts 400-599) — (§ 141.0 To Parts 193-199) — U.S. Customs And Border Protection, Department Of Homeland Security; Department Of The Treasury (Continued) (§ 141.0 To Parts 193-199) — Mail Importations (§ 145.0 To Appendix To Part 145) — General Provisions (§ 145.1 To § 145.5) — Undeliverable packages.