Art 49. The Detaining Power may utilize the labour of prisoners of war who are physically fit, taking into account their age, sex, rank and physical aptitude, and with a view particularly to maintaining them in a good state of physical and mental health. Non-commissioned officers who are prisoners of war shall only be required to do supervisory work. Those not so required may ask for other suitable work which shall, so far as possible, be found for them. If officers or persons of equivalent status ask for suitable work, it shall be found for them, so far as possible, but they may in no circumstances be compelled to work.