European Union – Customs and excise duties. The Combined Nomenclature set out in Annex I to Council Regulation (EEC) No 2658/87, as amended by Commission Implementing Regulation (EU) 2015/1754, should be interpreted as meaning that spinal fixation systems such as those at issue in the main proceedings could not be classified under subheading 9021 90 90 of the Combined Nomenclature if they were covered by another subheading of heading 9021 of the Combined Nomenclature. The Court of Justice held that whether those systems could be classified under subheading 9021 10 10 or subheading 9021 10 90 of the Combined Nomenclature would depend on the principal function they performed, which was a matter for the referring court to determine by having regard to the objective characteristics and properties of such systems as well as to their intended and actual use.