Related Rule
Practice Relating to Rule 79. Weapons Primarily Injuring by Non-Detectable Fragments
Sweden’s IHL Manual (1991) states:
[The 1980] Protocol I to the Convention on Certain Conventional Weapons relates to certain fragmentation weapons. The Protocol forbids the use of weapons whose primary effect is to injure by fragments which cannot be detected by X-raying the injured person. 
Sweden, International Humanitarian Law in Armed Conflict, with reference to the Swedish Total Defence System, Swedish Ministry of Defence, January 1991, Section 3.3.2, p. 79.