Concealment under Explanation to penalty provision: Supreme Court said questions of law may require Tribunal references. The Supreme Court found that Tribunal conclusions about concealment under the Explanation to the penalty provision raised questions of law warranting a statement of case under the departmental reference procedure, despite recurring Tribunal practice of treating such matters as questions of fact; the decision may guide framing departmental reference questions where repeated estimated assessments, wide discrepancies between returned and assessed incomes, excess self-assessments and similar payments are relied upon to allege concealment.