Règle correspondante
Practice Relating to Rule 1. The Principle of Distinction between Civilians and Combatants
Section C. Attacks against civilians
The Joint Circular on Adherence to IHL and Human Rights (1991) of the Philippines states:
When the use of armed force is inevitable, strict controls must be exercised to insure that only reasonable force necessary for mission accomplishment shall be taken and shall be directed only against hostile elements, not against civilians or non-combatants. 
Philippines, Implementation Guidelines for Presidential Memorandum Order No. 393, dated 9 September 1991, Directing the Armed Forces of the Philippines and the Philippines National Police to Reaffirm their Adherence to the Principles of Humanitarian Law and Human Rights in the Conduct of Security/Police Operations, Joint Circular Number 2-91, Department of National Defense, Department of Interior and Local Government, 1991, § (2)(a)(2).
The Air Power Manual (2000) of the Philippine Air Force provides:
6-3. Centers of Gravity
Centers of Gravity are the keys to targeting. A center of gravity is that point where the enemy is most vulnerable which, if successfully attacked, is most likely to bring about his defeat. If there are numerous centers of gravity, they may all have to be successfully attacked for the objective to be achieved. Correctly identifying centers of gravity in relation either to the overall strategic objective or to the immediate tactical objective (depending on the state of the conflict) and then determining how best to attack them is crucial to the air campaign plan.
6-4.4. Centers of gravity are both strengths and weaknesses. An analysis of Warden’s generic strategic centers of gravity indicates that they can be represented by five concentric rings. Starting at the innermost and most important ring and working outwards, those centers are:
a. national leadership,
b. key production,
c. infrastructure,
d. national will, and
e. fielded military forces.
6-5.1. One model proposed to aid target selection is that put forward by Colonel John Warden, USAF. Warden proposes a model, comprising five concentric rings representing the enemy’s centers of gravity, with the inner ring representing the most important center of gravity. According to this model, when attack of the enemy command is not feasible, it is possible to render the enemy impotent by destroying one or more of the outer strategic rings or centers of gravity. Importantly, Warden stresses that
“all actions are aimed at the mind of the enemy command. Thus, one does not conduct an attack against industry or infrastructure because of the effect it might or might not have on fielded forces. Rather, one undertakes such an attack for its effect on national leaders and commanders who must assess the cost of rebuilding the effects on the state’s economic position on the post war, the internal political effect on their own survival, and on the cost versus the potential gain from continuing the war.”
6-5.2. The fourth ring in Warden’s model may appear to condone the targeting of non-combatant civilian population which is contrary to the law of armed conflict (LOAC). To eliminate any possibility of misconception, it should be stressed that targeting does not automatically infer the use of lethal weapons. Non-lethal weapons such as psychological operations may legitimately be used to target the enemy population. The use of leaflet drops and media broadcasts are well known methods of targeting civilian population. Other methods have also been used to disrupt the orderly function of enemy society through the conversion of key personnel to one’s own cause and the incitement of parts of the enemy society to rebel against their leadership. These are non-destructive means of targeting the enemy population. Hence, the fourth ring in Warden’s model is a legitimate center of gravity that should not be ignored. 
Philippines, Air Power Manual, Philippine Air Force, Headquarters, Office of Special Studies, May 2000, §§ 6-3, 6-4.4. and 6-5.1.–6-5.2.