Related Rule
Ecuador
Practice Relating to Rule 57. Ruses of War
Ecuador’s Naval Manual (1989) states:
The law of armed conflicts permits deceiving the enemy through stratagems and ruses of war intended to mislead him, to deter him from taking action, or to induce him to act recklessly, provided the ruses do not violate rules of international law applicable to armed conflict.
Stratagems and ruses of war permitted in armed conflict include such deceptions as camouflage, deceptive lighting, dummy ships and other armament, decoys, simulated forces, feigned attacks and withdrawals, ambushes, false intelligence information, electronic deceptions, and utilization of enemy codes, passwords, and countersigns. 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, §§ 12.1 and 12.1.1.