Mechanically, this Order declares that specified parts for alumina‑hydrate filtration (barrels, drums, discs/disc sectors, troughs, supports, heads) classified at tariff heading 8421.99.00 are covered by Schedule 4, Part III item 50, effective 27 June 2006 until revoked (made under Customs Act 1901 s269P). That means importers may claim the Schedule 4 tariff concession for these goods; the CEO’s delegate issues and may revoke the order, so correct classification, documentation and compliance determine who benefits.