Determining the scope ratione personae of European citizenship: customary international law prevails for now ECJ, Judgment, 20 February 2001, Case C-192/99, The Queen v. Secretary of State for the - Legal Issues of Economic Integration View Determining the scope ratione personae of European citizenship: customary international law prevails for now ECJ, Judgment, 20 February 2001, Case C-192/99, The Queen v. Secretary of State for the by - Legal Issues of Economic Integration Determining the scope ratione personae of European citizenship: customary international law prevails for now ECJ, Judgment, 20 February 2001, Case C-192/99, The Queen v. Secretary of State for the 28 3 Legal Issues of Economic Integration