37The applicant submits that the principle that penalties must have a proper legal basis is intended to apply both to criminal penalties and to penalties which are not strictly criminal in character, and therefore also to Article 15(2) of Regulation No 17, regardless of the legal nature of the fines imposed by the Commission under that provision. The Court of Justice has held that ‘a penalty, even of a non-criminal nature, cannot be imposed unless it rests on a clear and unambiguous legal basis’ (Case 117/83Könecke [1984] ECR 3291, paragraph 11, and Case 137/85Maizena [1987] ECR 4587, paragraph 15). The statement in Article 15(4) of Regulation No 17, that Commission decisions imposing fines for infringements of Community competition law ‘shall not be of a criminal law nature’, is immaterial in this regard, since the designation of a legal act is not decisive in its assessment (Eur. Court HR, Engel and Others v. the Netherlands, judgment of 8 June 1976, Series A No 22, § 81). On the contrary, it follows from the severity of the fines imposed and from their punitive and preventive function that they are essentially of a quasi-criminal, or even, in the broad sense, criminal law nature.