Related Rule
Brazil
Practice Relating to Rule 70. Weapons of a Nature to Cause Superfluous Injury or Unnecessary Suffering
In 1974, during discussions in the Ad Hoc Committee on Conventional Weapons established by the CDDH, Brazil stated:
In principle, all available weapons could cause unnecessary suffering … depending on how they were used. There were good humanitarian reasons for the international community to agree at least on restricting the use of incendiary weapons against targets which were not exclusively military. 
Brazil, Statement at the CDDH, Official Records, Vol. XVI, CDDH/IV/SR.2, 14 March 1974, p. 18, § 7.
In 1993, the permanent representative of Brazil to the UN and other international organizations in Geneva wrote an article in which he declared: “Since the time when chemical weapons were first used, the Brazilian Government has consistently argued against the use of these and all other inhumane means of warfare.” He added: “The word ‘inhumane’ is employed here, in accordance with common usage, to mean weapons that cause unnecessary devastation and suffering.” 
Celso L. N. Amorim, “The Chemical Weapons Convention and the Security and the Developments Needs of Brazil”, Disarmament, Vol. 16, 1993, No. 1, p. 111.