Customs declarations made by any other act. ... The following, where not expressly declared to customs, shall be considered to have been declared for release for free circulation by the act referred to in Article 233: (a) goods of a non-commercial nature contained in travellers' personal luggage entitled to relief either under Chapter I, Title XI of Council Regulation (EEC) No 918/83 (10), or as returned goods; (b) goods entitled to relief under Chapter I, Titles IX and X of Council Regulation (EEC) No 918/83; (c) means of transport entitled to relief as returned goods; (d) goods imported in the context of traffic of negligible importance and exempted from the requirement to be conveyed to a customs office in accordance with Article 38 (4) of the Code, provided they are not subject to import duty.