Related Rule
France
Practice Relating to Rule 71. Weapons That Are by Nature Indiscriminate
France’s LOAC Teaching Note (2000) states that, “because of their indiscriminate effects”, the use of poison, chemical weapons, biological and bacteriological weapons, dum-dum bullets or other projectiles with expanding heads, anti-personnel mines, weapons that injure by non-detectable fragments, blinding laser weapons, and torpedoes without self-destruction mechanisms “is totally prohibited by the law of armed conflicts”. 
France, Fiche didactique relative au droit des conflits armés, Directive of the Ministry of Defence, 4 January 2000, annexed to the Directive No. 147 of the Ministry of Defence of 4 January 2000, p. 6.
France’s LOAC Manual (2001) states that weapons that have “indiscriminate effects” are prohibited. 
France, LOAC Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, p. 53.
The manual adds that, “because of their indiscriminate effects”, the use of poison, chemical weapons, biological and bacteriological weapons, dum-dum bullets or other projectiles with expanding heads, anti-personnel mines, weapons that injure by non-detectable fragments, blinding laser weapons, and torpedoes without self-destruction mechanisms “is totally prohibited by the law of armed conflicts”. 
France, Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, p. 54.
In 1974, during discussions in the Ad Hoc Committee on Conventional Weapons established by the CDDH, France stated:
29. … Each weapon, with its characteristics, its effects and its method of use, had to be considered separately, if specific conclusions have to be reached.
30. … The more important concept of indiscriminate effects might perhaps be applicable to some weapons, but related more often to their method of use. For instance, the mine became indiscriminate only when used as a drifting mine. Indiscriminateness lay much more in the use made of a weapon and in the brain of the commanding officer than in the weapon itself. 
France, Statement at the CDDH, Official Records, Vol. XVI, CDDH/IV/SR.15, 7 March 1975, p. 146, §§ 29–30.
In its written statement submitted to the ICJ in the Nuclear Weapons (WHO) case in 1995, France stated:
The fact that the [CDDH] took into consideration only conventional weapons also follows from the creation therein of an ad hoc commission on “conventional weapons”. Moreover, by its resolution 22, it [the CDDH] recommended the convocation of a conference “with a view to reaching a) agreements on prohibitions or restrictions on the use of specific conventional weapons including those which may be deemed to … have indiscriminate effects, taking into account humanitarian and military considerations; and b) agreement on a mechanism for the review of any such agreements and for the consideration of proposals for further such agreement”.
It furthermore appears that the States which participated in the conference considered that the rules figuring in the protocol cannot in themselves suffice to establish the illegality of the use of specific weapons, to whatever type they might belong.
Also, one cannot but ascertain the absence of a customary rule prohibiting the use of nuclear weapons.
It is true that a certain trend of opinion tries to prove the existence of a legal principle of the prohibition of nuclear weapons not by relying on positive norms specifically dealing with such weapons, but by constructing a reasoning on the basis of other rules of international law. Without directly mentioning the weapons in question, it is said that these rules could be applied to them [i.e. the weapons], by way of implication or by way of extension. For instance, the idea is sometimes put forward that certain rules in force of humanitarian law and the law of war would involve the prohibition of nuclear weapons. The supporters of that theory base themselves especially on diverse rules or principles enunciated in [the 1977 Additional Protocol I] – without questioning which [of these rules] are of customary nature and which are of conventional nature – and especially … the prohibition of indiscriminate attacks in the terms of article 51 of the protocol …
The government of France does not deem it necessary … to discuss in detail such reasoning, which it formally rejects … Indeed, if one cannot contest that protocol I of 1977 expresses, in some respects, general basic principles of existing law, it is obvious that … with respect to others, it constitutes a development …
Moreover, to follow the reasoning recalled above, once the basic customary principles applicable to nuclear weapons were drawn out and defined, one would have to establish that a rule prohibiting the use of these weapons follows from it. 
France, Written statement submitted to the ICJ, Nuclear Weapons (WHO) case, June 1994, pp. 27–31, §§ 23–26.
In 2009, the Minister of Foreign and European Affairs of France stated:
[B]oth Israel and Hamas have used weapons that have indiscriminate effects, since aerial bombing and mortar fire were not used in such a manner as to spare civilians. Yet the prohibition of the use of weapons with indiscriminate effects is another key principle of international humanitarian law. 
France, Minister of Foreign and European Affairs, “The Savaging of Humanitarian Law”, New York Times, 28 January 2009, p. 2.