Related Rule
Ecuador
Practice Relating to Rule 35. Hospital and Safety Zones and Neutralized Zones
Ecuador’s Naval Manual (1989) states: “When established by agreement between belligerents, hospital zones and neutralized zones are immune from bombardment in accordance with the terms of the agreement concerned.” 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, § 8.5.1.3.