Related Rule
Practice Relating to Rule 156. Definition of War Crimes
Nigeria’s Manual on the Laws of War states:
“War crime” is the technical term for violation of the Laws of war. It includes plotting, incitement or attempt to commit such crimes, as well as participation in the execution of these crimes. Grave breaches of the Geneva Conventions are considered as serious war crimes when committed against [a number of protected persons and objects listed within the provision]. 
Nigeria, The Laws of War, by Lt. Col. L. Ode PSC, Nigerian Army, Lagos, undated, § 6.