Chapter 4 examines which questions can be referred for a preliminary ruling. The European Court of Justice has jurisdiction to give preliminary rulings on the interpretation of the Treaties, and on the validity and interpretation of acts of the institutions, bodies, offices, or agencies of the Union. It does not have jurisdiction to rule on the interpretation or validity of international law or national laws, and it is prevented from giving a binding ruling on the facts that are put before a national court. Chapter 4 explains the reference to ‘the Treaties’ as well as the meanings of ‘acts’, ‘institutions, bodies, offices or agencies’, and ‘validity’. This examination includes police and judicial cooperation, common foreign and security policy, the Euratom Treaty and the ECSC Treaty, and it includes preliminary references concerning international agreements. The chapter also examines the extent to which the Court of Justice can give its opinion on the facts or the content of national law in connection with a reference for a preliminary ruling or on questions that concern circumstances that arise before a Member State’s accession to the European Union or where the preliminary ruling is rendered after a Member State’s withdrawal from the Union (eg Brexit).