Case C-635/20 P: Judgment of the Court (First Chamber) of 16 February 2023 — European Commission v Italian Republic, Kingdom of Spain (Appeal — Rules on languages — Notice of open competitions for the recruitment of administrators’ functions as investigators and team leaders — Knowledge of languages — Restriction of the choice of the second competition language to English, French and German — Language of communication with the European Personnel Selection Office (EPSO) — Regulation No 1 — Staff Regulations — Article 1d(1) — Difference in treatment based on language — Justification — Interests of the service — Requirement to recruit administrators who are ‘immediately operational’ — Judicial review — Standard of proof required)