Concealment presumption in wealth-tax searches triggers penalty despite later returns unless prior books or disclosure. Explanation 5 to section 18(1) deems assets found in a search under section 37A to be concealed or inaccurately stated for penalty under clause (c) unless, before the date of the search, those assets were recorded in the assessee's books of account (for earlier valuation dates, recorded before the search; for valuation dates on or after the search, recorded on or before that valuation date) or were otherwise disclosed to the Commissioner before the date of the search.