Part III : Captivity #Section II : Prisoners of war camps #Chapter 6 : Special provisions concerning officers and persons of equivalent status - Art. 21.
Art. 21. At the commencement of hostilities, belligerents shall be required reciprocally to inform each other of the titles and ranks in use in their respective armed forces, with the view of ensuring equality of treatment between the corresponding ranks of officers and persons of equivalent status.
Officers and persons of equivalent status who are prisoners of war shall be treated with due regard to their rank and age.