Exemption under section 10(46) grants specified income relief to a municipal development trust subject to non-commercial and filing conditions. Notification grants exemption under section 10(46) to West Bengal Municipal Development Fund Trust for specified income: interest from bank deposits, interest on term loans to urban local bodies, and upfront processing fees, subject to conditions prohibiting commercial activity, requiring unchanged activities and income nature across years, and mandating return filing as per the relevant provision of section 139; effective for specified past and current financial years.