International organizations — Immunity — Officials — United Nations — Second category officials — Fiscal exemption — Switzerland-United Nations Headquarters Agreement, 1946, Article V, Section 15(b) — Vienna Convention on Diplomatic Relations, 1961, Articles 34 and 38 — Whether exemption extends to Swiss nationals domiciled abroad — Advance tax deduction — Reimbursement for various categories of exempted persons — Expert attached to Office of Technical Cooperation for work in Gabon — Entitlement to reimbursement

Diplomatic relations — Immunity — Vienna Convention on Diplomatic Relations, 1961 — The law of Switzerland