What rules of EU law in the field of direct taxes are clear and can be applied at the national level without additional interpretative guidance of the Court of Justice of the European Union (CJEU)? This article applies computational methods, and network science in particular, to analyse which rules of EU law in the field of direct taxes may be considered “clear”. The aim of this article is to find units of information which have replicated through repeated application in the CJEU’s rulings and are thus dominant in this functional field of EU law. All 185 rulings handed down by the CJEU in the field of direct taxes in the period between 1983 and 2012 are analysed. The product of this research is reported in the Annex in which the most important settled and well-established rules of EU law in the field of direct taxes are organized in a legally relevant manner.