TCO 0513451 (made under s269P of the Customs Act 1901) applies item 50 of Part III, Schedule 4 of the Customs Tariff Act 1995 to a narrowly described imported yarn: polyamide multifilament, textured, denier 70–180 (tariff 5402.31.00) from 30 Sep 2005 until revoked. Mechanically, it changes the tariff treatment that applies to that precise product. Importers receive the altered duty treatment and the Commonwealth’s tariff revenue changes; the decision is made by a delegate of the Chief Executive Officer and compliance turns on correct tariff classification and denier verification.