Related Rule
Japan
Practice Relating to Rule 85. The Use of Incendiary Weapons against Combatants
At the Preparatory Conference for the Convention on Certain Conventional Weapons in 1978, Japan declared that while it “was not sure it would be practicable to ban completely” all incendiary weapons, the use of incendiary weapons containing yellow phosphorus should be prohibited. 
Japan, Statement at the Preparatory Conference for the Convention on Certain Conventional Weapons, UN Doc. A/CONF.95/PREP.CONF./I/ SR.12, 12 September 1978, p. 2, § 3.