Switzerland
Practice Relating to Rule 142. Instruction in International Humanitarian Law within Armed Forces
Section B. Obligation of commanders to instruct the armed forces under their command
Switzerland’s Basic Military Manual (1987) states: “Commanders must inform the troops of their obligations under the Conventions.”
Switzerland’s Regulation on Legal Bases for Conduct during an Engagement (2005) states:
4 Respect for and implementation of the legal rules in all types of operation are a command task and an integral part of individual discipline.
…
7 Responsible and lawful behaviour requires knowledge of the rules in force. Ignorance of the law does not protect against punishment. Superiors are therefore responsible for providing sufficient and realistic training to their subordinates.
…
248 Superiors are also responsible for training their subordinates and periodically testing their knowledge, especially prior to operations to which the law of armed conflict could apply.

[emphasis in original]