Chapter II: On Spies

ARTICLE XXIX.
An individual can only be considered a spy if, acting
clandestinely, or on false pretences, he obtains, or seeks to
obtain information in the zone of operations of a belligerent,
with the intention of communicating it to the hostile party.
Thus, soldiers not in disguise who have penetrated into the
zone of operations of a hostile army to obtain information are
not considered spies. Similarly, the following are not
considered spies: soldiers or civilians, carrying out their
mission openly, charged with the delivery of despatches
destined either for their own army or for that of the enemy.
To this class belong likewise individuals sent in balloons to
deliver despatches, and generally to maintain communication
between the various parts of an army or a territory.

ARTICLE XXX.
A spy taken in the act cannot be punished without previous
trial.

ARTICLE XXXI.
A spy who, after rejoining the army to which he belongs, is
subsequently captured by the enemy, is treated as a prisoner
of war, and incurs no responsibility for his previous acts of
espionage.