Excise duty exemption for specified goods conditional on reversal of input tax credit for past non levy practice. The notification directs that the whole of duty of excise leviable under the Central Excise Act on specified tariff sub headings was not required to be paid for defined past periods due to a prevailing practice of non levy; relief for manufacturers is conditional on reversal of any input tax credit taken for inputs used in the manufacture of those goods during the relevant periods.