31It must be recalled that, according to settled case-law, procedural rules are generally held to apply to all proceedings pending at the time when they enter into force, whereas substantive rules are usually interpreted as not applying, in principle, to situations existing before their entry into force (see, inter alia, Salumi and Others, paragraph 9; Joined Cases C-121/91 and C-122/91CT Control (Rotterdam) and JCT Benelux v Commission [1993] ECR I-3873, paragraph 22; Case C-61/98De Haan [1999] ECR I-5003, paragraph 13; and Case C-251/00Ilumitrónica [2002] ECR I-10433, paragraph 29).