Unexplained credits treated as taxable income unless named contributors provide satisfactory explanations acceptable to the assessing officer. Section 102 taxes sums credited in an assessee's books as income where the assessee offers no explanation or an explanation the Assessing Officer finds unsatisfactory. Credits characterized as loans or similar amounts are deemed not satisfactory unless the named person also provides a satisfactory explanation acceptable to the Assessing Officer; analogous treatment applies to private company credits recorded as share application money, share capital, share premium or similar amounts. Sub-sections (2) and (3) do not apply where the named person is a specified venture capital fund or company.