Règle correspondante
Practice Relating to Rule 16. Target Verification
The Report on the Practice of Jordan notes that a booklet on the law of armed conflict prepared by the ICRC is used by military commanders. The booklet gives a list of principles to apply in military action, among which is the obligation to verify the military nature of an objective prior to the attack. 
Report on the Practice of Jordan, 1997, Answers to additional questions on Chapter 1.6.