International organizations — Legal status — European School in Mol (Belgium) — Legal basis upon which the fees are charged for pupils whose parents are not Community officials or representatives of Member States — Statute of European School, 1957, and Establishment Protocol, 1962

Treaties — Conclusion and operation — Constitutional limitations — Whether any rule of international law giving States the right to conclude treaties contrary to their constitutions — Requirement under international agreement that the parents of certain pupils at European School should pay tuition fees — Whether violating right to free education under Belgian Constitution (Article 17(3)) and European Convention on Human Rights (Additional Protocol No. 1, Article 2) — The law of Belgium