This column shall be filled in with the numbers of Customs Handbook of the People's Republic of China for Registration of Processing Imported Materials, Customs Handbook of the People's Republic of China for Registration of Processing & Assembling and Small- and Medium-sized Compensation Trade, Customs Handbook of the People's Republic of China for Registration of Processing Imported Materials and Parts Required for Performance of Product Export Contracts by Foreign-funded Enterprises, electronic account-books and their volumes, Duty Levying/Exemption Certificate for Imported/Exported Goods, and other relevant registration and approval documents, given by the Customs when the export/import enterprise applies to the Customs for approval, registration or other formalities relevant to processing trade contract, or relevant to tax levy, reduction and exemption. For the Customs Declaration Form without registration or approval documents, this column can be left blank.