Règle correspondante
Practice relating to Rule 66. Non-Hostile Contacts between the Parties to the Conflict
Section B. Use of the white flag of truce
Nigeria’s Manual on the Laws of War notes:
The hoisting of a white flag means that a belligerent wishes to communicate with the enemy, either for the purpose of surrender or for some other purposes. Hoisting the white flag by a small number of soldiers usually [expresses] the wish to surrender; in the case of a large unit it is usually the expression of a wish to conduct negotiations. 
Nigeria, The Laws of War, by Lt. Col. L. Ode PSC, Nigerian Army, Lagos, undated, § 24.