27It is settled law that the prohibition of quantitative restrictions and of all measures having equivalent effect applies not only to national measures but also to measures adopted by the Community institutions (see in particular to this effect Case 15/83Denkavit Nederland v Hoofdproduktschap voor Akkerbouwprodukten [1984] ECR 2171, paragraph 15, and Case C-51/93Meyhui v Schott Zwiesel GUswerke [1994] ECR I-3879, paragraph 11).