171In the present case, by failing to provide the necessary clarification, the Council and the Commission infringed the principle of legal certainty. Moreover, the Commission infringed the principles of sound administration and good faith by failing to respond to the applicant's requests (Joined Cases 43/59, 45/59 and 48/59 Von Lachmüller and Others v Commission [1960] ECR 463 and Case 179/82Lucchini v Commission [1983] ECR 3083).