Excise duty exemption for articles intended as permanent magnets; excess duty need not be paid where it was not levied. Central Government directs that the whole of the duty of excise or the portion in excess of the duty payable on permanent magnets under the specified notification shall not be required to be paid in respect of articles intended to become permanent magnets on which duty was not levied in accordance with the prevalent practice during the relevant period, issued under the powers of section 11C of the Central Excises and Salt Act, 1944.