Tariff amendment inserts polyethylene terephthalate into the excise schedule, specifying an ad valorem duty rate under the notification. The Government amends Notification No. 53/88-Central Excises by inserting a new serial entry designating tariff heading 3907.60 for Polyethylene terephthalate (polyester polymer chips) with a 20% ad valorem specification, added to the table after the existing Sl. No. 12.