Opinion of Advocate General Szpunar delivered on 6 June 2024.#Sindicato de Tripulantes Auxiliares de Vuelo de Líneas Aéreas (STAVLA) and Ministerio Fiscal v Air Nostrum and Others.#Request for a preliminary ruling from the Audiencia Nacional.#Reference for a preliminary ruling – Social policy – Equal treatment between men and women in matters of employment and occupation – Directive 2006/54/EC – Article 2(1)(e) – Concept of ‘pay’ – Article 4 – Prohibition of indirect discrimination on grounds of sex.#Case C-314/23.