Judgment_paragraph 31 · Crono Service scarl and Others and Anitrav — Associazione Nazionale Imprese Trasporto Viaggiatori v Roma Capitale and Regione Lazio (C-419/12, C-420/12)

31As regards, first, the EU competition rules, the Court has consistently held that the need to provide an interpretation of EU law which will be of use to the referring court requires that court to define the factual and legal context of its questions or, at the very least, to explain the factual circumstances on which those questions are based. Those requirements are of particular importance in the field of competition, which is characterised by complex factual and legal situations (see, inter alia, Attanasio Group, paragraph 32 and the case-law cited, and Joined Cases C‑357/10 to C‑359/10 Duomo Gpa and Others [2012] ECR, paragraph 22).