(11)(a)The Central Government may, by notification, specify any class or classes of persons who shall apply to the Assessing Officer for the allotment of Permanent Account Number within such time as mentioned in such notification;(b)the class or classes of persons in clause (a) may include such persons––(i)by whom tax is payable under this Act; or(ii)by whom any tax or duty is payable under any other law in force; or(iii)being importers and exporters, even when no tax is payable by them.