Art. 18. A town taken by storm should not be given up to the victorious troops to plunder.
Chapter V. Of Spies
Art. 19. No one shall be considered as a spy but those who, acting secretly or under false pretenses, collect, or try to collect information in districts occupied by the enemy with the intention of communicating it to the opposing force.
Art. 20. A spy, if taken in the act, shall be tried and treated according to the laws in force in the army which captures him.
Art. 21. If a spy, who rejoins the army to which he belongs, is subsequently captured by the enemy, he is to be treated as a prisoner of war, and incurs no responsibility for his previous acts.
Art. 22. Military men who have penetrated within the zone of operations of the enemy's army, with the intention of collecting information, are not considered as spies if it has been possible to recognize their military character.
In like manner military men (and also non-military persons carrying out their mission openly), charged with the transmission of dispatches either to their own army or to that of the enemy, shall not be considered as spies if captured by the enemy.
To this class belong also, if captured, individuals sent in balloons to carry dispatches, and generally to keep up communications between the different parts of an army, or of a territory.
Chapter VI. Of Prisoners of War
Art. 23. Prisoners of war are lawful and disarmed enemies. They are in the power of the enemy's Government but not of the individuals or of the corps who made them prisoners.