control

... They shall continue to exercise their medical and spiritual functions for the benefit of prisoners of war, preferably those belonging to the armed forces upon which they depend, within the scope of the military laws and regulations of the Detaining Power and under the control of its competent services, in accordance with their professional etiquette. They shall also benefit by the following facilities in the exercise of their medical or spiritual functions: ...

... Every labour detachment shall remain under the control of and administratively part of a prisoner of war camp. The military authorities and the commander of the said camp shall be responsible, under the direction of their government, for the observance of the provisions of the present Convention in labour detachments. ...

... If relief shipments intended for prisoners of war cannot be sent through the post office by reason of weight or for any other cause, the cost of transportation shall be borne by the Detaining Power in all the territories under its control. The other Powers party to the Convention shall bear the cost of transport in their respective territories. ...

... 2. He has left the territory under the control of the Detaining Power, or of an ally of the said Power; ...

... 3. He has joined a ship flying the flag of the Power on which he depends, or of an allied Power, in the territorial waters of the Detaining Power, the said ship not being under the control of the last-named Power. ...