Tax exemption under clause 23C(iv) requires trusts to apply income to charitable objects, restrict investments, and file returns. Notification under clause (23C)(iv) of section 10 notifies Children Book Trust as eligible for exemption for assessment years 2001-2002 to 2003-2004, subject to conditions: apply or accumulate income wholly for its objects; invest only in forms specified in sub section (5) of section 11 (except certain voluntary contributions held as jewellery, furniture, etc.); business income excluded unless incidental and kept in separate books; regular filing of income-tax returns; and transfer of surplus assets on dissolution to a like charitable organization.