Maximum marginal rate applies to trust or wakf income when beneficiary shares are indeterminate or not specified. Amendments require that relevant income of trusts, associations or wakfs which is not specifically receivable for identifiable beneficiaries, or where beneficiary shares are indeterminate, be taxed by applying the maximum marginal rate. For mixed income, tax is the aggregate of: tax on charitable or religious portions (after applicable exemptions) computed as if that part were the total income of an association of persons, and tax on non-charitable portions at the maximum marginal rate. Explanations treat income as not specifically receivable unless beneficiary identity or shares are expressly stated and ascertainable in the instrument or order.