Certification means the confirmation of compliance with a pre-defined standard relating to a business, a product, a service or a management system. That standard can be a public law standard, a private standard or a hybrid.1 Certification has become a hot topic, in particular at the European level. It is a popular instrument of private governance of public goods, promising greater effectiveness than control by public authorities while at the same time taking the burden away from the State and its budget. Being a private instrument, it had long been attributed to the private sphere; which has changed drastically through recent decisions of the Court of Justice of the European Union (CJEU) that take into consideration the immense factual power of at least some private actors with regard to the facilitation of trade or to creating obstacles to trade. In the case of Fra.bo,2 the German privately organised Deutsche Vereinigung des Gas- und Wasserfaches eV (DVGW) denied the certification of copper fittings for piping for water or gas, produced by the Italian producer Fra.bo. The Court held that Article 28 TFEU on the free movement of goods must be interpreted as meaning that it applies to standardisation and certification activities of a private-law body, where the national legislation considers the products certified by that body to be compliant with national law and that has the effect of restricting the marketing of products which are not certified