International organizations — Immunity — Officials — International Court of Justice — Agreement between International Court of Justice and the Netherlands, 1946 — Agreement conferring diplomatic status on Deputy Registrar of Court — Tenancy agreement — Action for eviction against Deputy Registrar for breach of agreement — Whether Deputy Registrar immune from civil jurisdiction — Vienna Convention on Diplomatic Relations, 1961 — Article 31(1)(a) of Convention — Exception to immunity — Action relating to private immovable property situated in territory of receiving State — Whether including action for eviction — Request by Court that Deputy Registrar live near place of employment — Whether affecting private status of property — Criteria for determining whether property being used for private purposes

Sources of international law — Treaties — Customary international law — Vienna Convention on Diplomatic Relations, 1961 — Whether declaratory of customary international law

Treaties — Ratification — Effect of non-ratification — Provisions declaratory of customary international law — Interpretation — Object and purpose — Vienna Convention on Diplomatic Relations, 1961, Article 31(1)(a)

Diplomatic relations — Immunity — Diplomatic status conferred on official of international organization — Applicability of Vienna Convention on Diplomatic Relations, 1961 — The law of the Netherlands