Discussions around formalism have made a comeback in the competition law community. This paper seeks to clarify, first, what term means – and does not mean. It is, in essence, an approach to the identification and the evaluation of the lawfulness of practices that relies on their formal features – and their formal features alone. Formalism should not be conflated with, inter alia, the ‘by object’ treatment of conduct and with the use of legal categories (which are a necessity). Second, the paper shows that the Court has consistently placed substance above form in its case law – as cases like Super Bock and Slovak Telekom show. On the other hand, competition authorities appear to favour formalism. The tension between the Court’s and authorities’ favoured approaches might be a source of legal uncertainty and might result in the fragmentation of the legal system along several dimensions.