Opinion of Advocate General Emiliou delivered on 8 March 2022.#Proceedings brought by Boriss Cilevičs and Others.#Request for a preliminary ruling from the Satversmes tiesa.#Reference for a preliminary ruling – Article 49 TFEU – Freedom of establishment – Restriction – Justification – The organisation of education systems – Institutions of higher education – Obligation to provide courses of study in the official language of the Member State concerned – Article 4(2) TEU – National identity of a Member State – Defence and promotion of the official language of a Member State – Principle of proportionality.#Case C-391/20.