++++ 1. Public contracts of the European Communities - Requirement that they be in writing - Oral changes - Not permissible (Financial Regulation, Art. 50) 2. Procedure - Application instituting the proceedings - Formal requirements - Summary of the pleas in law on which the application is based (Statute of the Court EAEC, Art. 19; Rules of Procedure, Art. 38) 3. Procedure - Action brought before the Court on the basis of an arbitration clause - Competence of the Court limited to the contractual dispute - Reliance on a plea in law based on undue enrichment - Precluded (EAEC Treaty, Art. 153)