Tax exemption for notified regulatory authority covers specified non-commercial receipts subject to activity and filing conditions. Notification grants tax exemption under section 10(46) to the 'Forum of Regulators' for government grants, membership fees from central and state electricity regulatory commissions, and interest on bank deposits, subject to conditions that the Forum shall not engage in commercial activity, that its activities and the nature of the specified income remain unchanged across the financial years, and that it files income-tax returns as required by clause (g) of sub-section (4C) of section 139; the notification is made retrospective for specified past financial years.