Charging section for additional customs duty clarified; excise on DTA clearances now capped by statutory ceiling under proviso to Central Excise Act. Supreme Court clarification that the charging provision for the additional duty of customs is not Section 12 necessitated amendment of notifications so that excise on DTA clearances by EOUs and FTZs is computed using aggregate customs duties read with the relevant notification but capped by the statutory ceiling in the proviso to the Central Excise Act; excise payable is the lesser of the aggregate customs duties and the statutory ceiling, effective from 16 September 1999.