This Tariff Concession Order (under s269P of the Customs Act 1901) treats certain oil‑ or gas‑exploration drilling rigs (tariff classification 8430.49.00 — slant single or telescopic double rigs) as subject to item 50 of Part III of Schedule 4 to the Customs Tariff Act 1995, effective 14 December 2005 until revoked (ss269SC/269SD). Mechanically, it changes the tariff treatment for importers of those specific rigs, so importers must show the goods match the description and face the administrative risk of revocation.