Tax on unexplained income: specified unaccounted receipts taxed separately with no deductions and aggregate tax on remaining income. A new provision taxes income identified as unexplained separately by levying a special tax on that income and then charging tax on the remaining income as if the unexplained income were excluded, with the taxpayer liable for the aggregate tax. No deduction or allowance is permitted in computing the unexplained income subject to the special tax, creating a bifurcated computation between separately taxed unexplained receipts and ordinarily taxed remaining income.