Treaties, States Parties and Commentaries
Treaties and Documents
Geneva Conventions of 1949 and Additional Protocols, and their Commentaries
Historical Treaties and Documents
Instructions for the Government of Armies of the United States in the Field (Lieber Code). 24 April 1863.
Section VII : Parole - Art. 123.
Art. 123. Release of prisoners of war by exchange is the general rule; release by parole is the exception.