In virtue of the Convention of Geneva,
74. Captivity ceases as of course, before the date fixed upon for general liberation, in the case of wounded or sick prisoners who, after being cured, are found to be incapable of further service.
The captor must send these back to their country so soon as their incapacity is established.
During the war
75. Prisoners can be released by means of a cartel of exchange negotiated between the belligerent parties.
Even without exchange
76. Prisoners can be set at liberty on parole, if the laws of their country do not forbid it. The conditions of their parole must be clearly stated. If so set at liberty, they are bound, on their honor, to fulfill scrupulously the engagements which they have freely entered into. Their government, on its part, must neither require nor accept from them any service inconsistent with their pledged word.
77. A prisoner cannot be compelled to accept his liberty on parole. In the same way the enemy government is not obliged to accede to a request made by a prisoner to be released on parole.
78. Prisoners liberated on parole and retaken in arms against the government to which they are pledged, can be deprived of the rights of prisoners of war, unless they have been included among prisoners exchanged unconditionally under a cartel of exchange negotiated subsequently to their liberation.
IV. Persons Interned in Neutral Territory