European Union – Public supply contracts. Article 34(8) of Directive (EC) 2004/17 should be interpreted as meaning that, when the technical specifications in the contract documentation referred to a specific mark, origin or production, the contracting authority should require the tenderer to submit, already in its tender, proof that the products which it proposed were equivalent to those defined in the technical specifications. The Court of Justice of the European Union so held in a preliminary ruling in proceedings concerning the award of a contract for the supply of original or equivalent spare parts for buses and trolley-buses bearing a company's specific mark.