European Union – Social security. The classification of a benefit under one of the branches of social security listed in art 3 of Regulation (EC) No 883/2004, made by the competent national authority in the declaration submitted by the member state pursuant to art 9(1) of that regulation, was not definitive. The Court of Justice of the European Union held that the classification of a social security benefit could be made by the national court concerned, autonomously and on the basis of the elements that constituted the social security benefit at issue, and by referring, if necessary, a question for a preliminary ruling to the Court.