European Union – Internal market. The Court of Justice of the European Union made a preliminary ruling concerning the interpretation of art 25 of Directive (EC) 2003/55 (concerning common rules for the internal market in natural gas and repealing Directive (EC) 98/30), and of arts 41 and 54 of Directive (EC) 2009/73 (concerning common rules for the internal market in natural gas and repealing Directive (EC) 2003/55). The reference had been made in proceedings between E.ON Földgáz Trade Zrt. and the Hungarian energy and public utility service regulator, concerning the amendment by that authority of the rules of the gas network code relating to long-term reserve capacity and managing congestion.