Tax exemption under Section 10(46): BIS specified incomes exempt subject to non commerciality and prescribed filing conditions. Notification under Section 10(46) designates the Bureau of Indian Standards as exempt for specified income-certification fees, sale of standards without profit, and interest-subject to conditions that BIS not engage in commercial activity, that its activities and the nature of the specified income remain unchanged, and that it files its return of income under the prescribed statutory provision; the notification applies for the financial years 2021-22 to 2025-26 and records no adverse effect from retrospective operation.