Customs exemption amendment updates tariff classifications for silicon products and undiffused wafers, altering schedule codes and duty treatment. The Central Government amends existing customs exemption notifications by substituting the Table entry in Notification No. 20/99-Cus. to list (A) silicon in all forms for manufacture of undiffused silicon wafers and (B) undiffused silicon wafers for manufacture of solar cells or solar cell modules, each with specified tariff code groupings and duty treatment; and by revising List A entries in Notification No. 25/99-Cus. to replace the column (2) schedule codes against two serial numbers, thereby updating the schedule cross-references for those exemptions.