Related Rule
Switzerland
Practice Relating to Rule 100. Fair Trial Guarantees
Section D. Information on the nature and cause of the accusation
Switzerland’s Basic Military Manual (1987) provides: “Every person arrested, detained or interned for acts committed in connection with the conflict shall be informed, without delay, in a language he or she understands, of the reasons why the measures have been taken.” 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 175.
Switzerland’s Criminal Procedure Code (2007), as amended to 2012, which regulates the prosecution and adjudication by the federal and cantonal criminal justice authorities of offences under federal law, including war crimes, states: “At the start of the examination hearing, the person being questioned shall, in a language they can understand: … be advised of the subject matter of the criminal proceedings and of the capacity in which he is being interviewed”. 
Switzerland, Criminal Procedure Code, 2007, as amended to 2012, Article 143(1)(b); see also Article 158(1)(a).
In 2010, in its Report on IHL and Current Armed Conflicts, Switzerland’s Federal Council stated:
3.4 [Increasing use] of anti-guerrilla tactics
Apart from the direct fight against insurgents, international humanitarian law also addresses other anti-guerrilla tactics. … If members of militias or opposition groups fall into the hands of the government they benefit from the protection of art. 75 of [the 1977] Additional Protocol I as well as that of art. 3 common to the [1949] Geneva Conventions. 
Switzerland, Federal Council, Report on IHL and Current Armed Conflicts, 17 September 2010, Section 3.4, p. 15.
[footnotes in original omitted]