Article 15 of the Provisional Regulations of the People's Republic of China on Value-added Tax (VAT) stipulates that items enjoying VAT exemption include self-produced agricultural products sold by agricultural producers, contraceptive medicines and paraphernalia, antique and old books, imported instruments and equipments directly used in scientific researches, scientific experiments and teachings, imported materials and equipments freely assisted by foreign governments and international organizations, items directly imported for the exclusive use of the disabled by the Organizations for the disabled directly imported for the exclusive use of the disabled, the sale of their own used items. The above VAT-exempt items must be issued with ordinary VAT invoices, and no special VAT invoices shall be issued.