Treaties, States Parties and Commentaries
Treaties and Documents
Geneva Conventions of 1949 and Additional Protocols, and their Commentaries
Historical Treaties and Documents
Project of an International Declaration concerning the Laws and Customs of War. Brussels, 27 August 1874.
Spies - Art. 19.
Art. 19. A person can only be considered a spy when acting clandestinely or on false pretenses he obtains or endeavours to obtain information in the districts occupied by the enemy, with the intention of communicating it to the hostile party.