Penalty under section 18(1)(a) requirement enforced: wealth-tax officers must levy the penalty and risk disciplinary action for lapses. The Board directs Wealth-tax Officers to impose the penalty u/s 18(1)(a) of the Wealth Tax Act wherever the provision applies, noting past failures to levy the penalty that caused revenue loss and adverse Revenue Audit comments; officers must ensure consistent application and face stringent disciplinary action for future lapses.