Documentation Requirements for Various Special Tariff Treatment Provisions

U.S. Customs and Border Protection (CBP) is responsible for determining whether imported articles that are classified under Harmonized Tariff Schedule (HTS) subheadings 9801.00.10 (US Goods Returned), 9802.00.20, 9802.00.25, 9802.00.40, 9802.00.50, 9802.00.60 and 9817.00.40 are entitled to duty-free or reduced duty treatment. When filing under these HTS provisions, the declarations provided for in 19 CFR 10.1(a), 10.8 (a), 10.9(a) and 10.121 must be in possession at time of entry and submitted to CBP upon request. CBP is asking for comments on the collection of information for the proper performance of the agency.

Requirements available here