Tax-free bonds under section 10(15)(iv): registration required to claim exemption on specified NEEPCO Series-IV bonds. The Central Government designates the North Eastern Electric Power Corporation Limited 1997-98 (Series-IV) bonds as tax-free under section 10(15)(iv), specifying one-lakh-rupee denominations issued in 1997-98 with distinctive serial numbers E-0000001 to E0002050, interest at 9.25% per annum for seven years and an authorized aggregate issue amount; the exemption is admissible only if the holder registers his name and holdings with the issuing company.