Judgment of the Court (Third Chamber) of 14 December 2023.#Jérôme Rivière and Others v European Parliament.#Appeal – Law governing the institutions – Members of the European Parliament – Rules of Procedure of the European Parliament – Standards of conduct – Rule 10(3) – Prohibition on displaying banners during the sittings of Parliament – Oral measure of the President of the Parliament prohibiting MEPs from displaying national flags on their lecterns – Action for annulment – Article 263 TFEU – Concept of ‘challengeable act’.#Case C-767/21 P.