Related Rule
New Zealand
Practice Relating to Rule 57. Ruses of War
New Zealand’s Military Manual (1992) states:
Ruses of war are measures taken to gain advantage over the enemy by mystifying or misleading him. They are permitted provided they are free from any suspicion of treachery or perfidy and do not violate any expressed or tacit agreement …
Legitimate ruses include: surprises; ambushes; feigning attacks, retreats or flights; simulating quiet and inactivity; giving large strongpoints to a small force; constructing works, bridges, etc., which it is not intended to use; transmitting bogus signal messages, and sending bogus despatches and newspapers with a view to their being intercepted by the enemy; making use of the enemy’s signals, watchwords, wireless code signs and tuning calls, and words of command; conducting a false military exercise on the wireless on a frequency easily interrupted while substantial troop movements are taking place on the ground; pretending to communicate with troops or reinforcements which do not exist; moving landmarks; constructing dummy airfields and aircraft; putting up dummy guns or dummy tanks; laying dummy mines; removing badges from uniforms; clothing the men of a single unit in the uniforms of several different units so that prisoners and dead may give the idea of a large force; giving false ground signals to enable airborne personnel or supplies to be dropped in a hostile area, or to induce aircraft to land in a hostile area.
… [I]t would not be unlawful for a few men to call upon an enemy force to surrender on the ground that it was surrounded or to threaten bombardment although no guns are actually in place. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, §§ 502(1), 502(2) and 502(3) (land warfare); see also § 611(1) (air warfare) and § 713(1) (naval warfare).