Related Rule
Practice Relating to Rule 1. The Principle of Distinction between Civilians and Combatants
Section A. The principle of distinction
Ukraine’s IHL Manual (2004) states:
Principle of distinction means that during preparation for and conduct of combat a clear distinction must be made between civilians and combatants [and] between civilian objects and military objectives, with a view to ensuring protection of the civilian population and civilian objects from the consequences of hostilities and to concentrating the actions of forces exclusively against the enemy’s military objects. 
Ukraine, Manual on the Application of IHL Rules, Ministry of Defence, 11 September 2004, § 2.1.7.