Соответствующая норма
Switzerland
Practice Relating to Rule 70. Weapons of a Nature to Cause Superfluous Injury or Unnecessary Suffering
Switzerland’s Basic Military Manual (1987) states that belligerents “must not use weapons, projectiles, toxic gases or means of combat that cause unnecessary suffering”. 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 17.
Switzerland’s Regulation on Legal Bases for Conduct during an Engagement (2005) states:
12 Four basic principles of the LOAC
158 …
- the principle of limitation.
12.4 The principle of limitation
164 The law of armed conflict prohibits recourse to prohibited means of warfare and restricts the use of weapons and means which cause unnecessary suffering or avoidable damage (see para. 227 et seq.). It also prohibits recourse to permitted weapons or means if it is foreseeable or knowingly foreseen that their use will cause unnecessary suffering or avoidable damage. 
Switzerland, Bases légales du comportement à l’engagement (BCE), Règlement 51.007/IVf, Swiss Army, issued based on Article 10 of the Ordinance on the Organization of the Federal Department for Defence, Civil Protection and Sports of 7 March 2003, entry into force on 1 July 2005, §§ 158 and 164.
In 1974, during discussions in the Ad Hoc Committee on Conventional Weapons established by the CDDH, Switzerland stated that the principle prohibiting unnecessary suffering “belongs to customary law” and was “already in force”. 
Switzerland, Statement at the CDDH, Official Records, Vol. XVI, CDDH/IV/SR.1, 13 March 1974, pp. 12–13, § 24.
Switzerland’s ABC of International Humanitarian Law (2009) states:
Hague Conventions
At the two peace conferences in The Hague in 1899 and 1907, several conventions were adopted for the purpose of regulating the conduct of war. One notable achievement was a ban on the use of Weapons which are of a nature to cause unnecessary suffering. …
Means and methods of warfare
Even in war not everything is allowed. … Weapons that cause Unnecessary suffering are expressly prohibited. There are a number of conventions that limit the choice of Weapons and prohibit the manufacture, stockpiling, transfer and deployment of specific weapons.
Unnecessary suffering
The prohibition with regard to causing unnecessary suffering is one of the fundamental principles of international humanitarian law. It imposes limits on the Means and methods of warfare. Combatants should suffer only the force necessary to put them hors de combat.
Weapons
International humanitarian law imposes limitations, in some cases a total ban, on the use of weapons whose impact goes beyond the permissible purpose of weakening the enemy. Weapons are prohibited on the basis of three fundamental criteria: if their use inevitably leads to death; if they cause disproportionate injury or Unnecessary suffering; if they strike indiscriminately. On the basis of these three criteria a number of specific weapons have been explicitly prohibited by international conventions, including Anti-personnel mines, Cluster munitions, blinding laser weapons, Dumdum bullets as well as Biological and Chemical weapons. Some of these bans are part of Customary international law. 
Switzerland, Federal Department of Foreign Affairs, ABC of International Humanitarian Law, 2009, pp. 22, 29 and 40.
In 2010, in its Report on IHL and Current Armed Conflicts, Switzerland’s Federal Council stated:
3.2 Increasing technification of war
… The weapon technologies used do not call into question the applicable principles of international humanitarian law. … Furthermore, attacks must not cause … unnecessary suffering. These fundamental principles are always applicable to all types and systems of weapons. 
Switzerland, Federal Council, Report on IHL and Current Armed Conflicts, 17 September 2010, section 3.2, p. 9.
In 2010, in its Report on Foreign Policy, Switzerland’s Federal Council stated that Switzerland “aims … to prohibit weapons producing excessively traumatic effects or striking without discrimination”. 
Switzerland, Federal Council, Report on Foreign Policy 2010, 10 December 2010, Section 4.5.2, p. 1137.
In 2013, in a statement at the Meeting of the High Contracting Parties to the Convention on Certain Conventional Weapons, the permanent representative of Switzerland stated:
The community of States cannot remain indifferent to the human suffering caused by armed conflicts. It was in direct response to this fundamental concern that the CCW [1980 Convention on Certain Conventional Weapons] and its protocols were adopted, with a view to prohibiting or limiting the use of certain specific types of weapon known to inflict superfluous injury or unnecessary suffering, or to strike indiscriminately. 
Switzerland, Statement by the permanent representative of Switzerland at the Meeting of the High Contracting Parties to the Convention on Certain Conventional Weapons, 14 November 2013.