This Order (under s 269P of the Customs Act 1901) applies a specific Schedule 4 tariff item (Item 50) to propylene randomly copolymerised with butene classified at 3902.30.00 (Table, Cols 1–2), effective 05.10.05 and continuing until revoked (ss 269SC/269SD). Mechanically, it changes which tariff treatment importers of that chemical must use; the delegate of the CEO makes the determination and revocation is an administrative act. Importers must classify consignments to rely on the concession and consult Schedule 4 to see the exact duty effect.