Declaration of undisclosed income permits voluntary disclosure of previously undeclared taxable income, with investments treated at fair market value. Persons may declare taxable undisclosed income for years before the 2017-18 assessment year if they failed to file returns, failed to disclose income in filed returns, or the income escaped assessment due to omission; where declared as investment in assets, the asset's fair market value at Scheme commencement is deemed the undisclosed income, with valuation to be prescribed and no deduction allowed against such declared income.