world loss "world loss", in relation to a certificate which is an acceptable certificate, means - (a) the amount of any loss specified in that certificate together with the amount of the depreciation allowances specified in that certificate; or (b) where the amount of those allowances exceeds the amount of the income specified in that certificate in accordance with paragraph (b) (ii) of the definition of "certificate" in this subsection, the amount of the excess. ACT 53 - INCOME TAX ACT 1967 54. Sea and air transport undertakings.