Treaties — Operation of — Relation to municipal law — Effect of action under municipal law contrary to treaty provision — Treaty establishing European Coal and Steel Community and Protocol on Privileges and Immunities — Tax improperly assessed by authorities of member State on income of family of Community official — Obligation of member State to withdraw assessment and make reparation.

International organization — International officials — Immunities of — Extent of immunity from taxation — Whether salary of official exempt from aggregation to determine rate of tax due on joint family income — Indirect taxation of salary — Protocol on Privileges and Immunities of European Coal and Steel Community, Article 11 (b) — Law applicable in interpreting this provision — Ratio legis of exemption from taxation.

Court of Justice of the European Communities — Access to — By individual official of Community in action against Government of his national State — Whether action should be brought by High Authority on behalf of official — Whether local remedies must be exhausted before appeal to Court admissible — Principle in Treaty of strict separation of powers of Court from those of municipal courts of member States — Protocol on Privileges and Immunities, Article 16 — Who are "parties " to "dispute" within Article 16.

Officials of international organizations — Right to privileges and immunities — European Coal and Steel Community — Immunity of officials from taxation — Extent of — Whether salary of official exempt from aggregation to determine rate of tax due on joint family income — Indirect taxation of salary — Whether local remedies must be exhausted before appeal to Court of Communities admissible — Protocol on Privileges and Immunities of Community, Article 11 (b) — Law applicable in Interpreting this provision — Relevance of Belgian law — Ratio legis of exemption from taxation — Exemption as “legitimate interest” of Community.