According to the traditional view, quantitative restrictions and discriminatory rules could be justified only according to the Treaty derogations contained in Article 30 of the EC Treaty. On the other hand, most indistinctly applicable measures, benefit also from other and broader grounds of justification: the mandatory (or imperative) requirements.
This distinction has been in recent years occasionally disregarded by the Court: this has led to a certain degree of confusion as to the theoretical explanation of the mandatory requirements doctrine. In particular doubts have been raised as to whether the mandatory requirements should not in fact be considered as additional grounds of derogation to those listed in Article 30 EC.