It is the duty of the besieged to indicate the presence of such buildings or places by distinctive and visible signs, which shall be notified to the enemy beforehand.
Article 28
The pillage of a town or place, even when taken by assault, is prohibited.
Chapter II. Spies
Article 29
A person can only be considered a spy when, acting clandestinely or on false pretences, he obtains or endeavours to obtain information in the zone of operations of a belligerent, with the intention of communicating it to the hostile party.
Thus, soldiers not wearing a disguise who have penetrated into the zone of operations of the hostile army, for the purpose of obtaining information, are not considered spies. Similarly, the following are not considered spies: Soldiers and civilians, carrying out their mission openly, intrusted with the delivery of despatches intended either for their own army or for the enemy's army. To this class belong likewise persons sent in balloons for the purpose of carrying despatches and, generally, of maintaining communications between the different parts of an army or a territory.
Article 30
A spy taken in the act shall not be punished without previous trial.
Article 31
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.
Chapter III. Flags of Truce
Article 32
A person is regarded as bearing a flag of truce who has been authorized by one of the belligerents to enter into communication with the other, and who advances bearing a white flag. He has aright to inviolability, as well as the trumpeter, bugler or drummer, the flag-bearer and interpreter who may accompany him.
Article 33
The commander to whom a flag of truce is sent is not in all cases obliged to receive it.
