Case C-627/22, Finanzamt Köln-Süd (Voluntary assessment requested by a partially taxable person): Judgment of the Court (First Chamber) of 30 May 2024 (request for a preliminary ruling from the Finanzgericht Köln – Germany) – AB v Finanzamt Köln-Süd (Reference for a preliminary ruling – Agreement between the European Union and the Swiss Confederation on the free movement of persons – Worker from a Member State who has transferred his residence to Switzerland – Tax concessions – Income tax – Voluntary assessment mechanism – Taxpayers who may benefit therefrom – Restriction to partially taxable employed persons resident in a Member State or in a State party to the Agreement on the European Economic Area (EEA) – Equal treatment)