Switzerland
Practice Relating to Rule 23. Location of Military Objectives outside Densely Populated Areas
Switzerland’s Basic Military Manual (1987) states: “To the extent possible, that is, as far as the interests of Swiss national defence allow, no military objective shall be placed within or in the vicinity of densely populated areas.”
Switzerland’s Regulation on Legal Bases for Conduct during an Engagement (2005) states:
165 The following precautionary measures must be taken into consideration when making decisions, when issuing orders and in particular when conducting military operations.
…
170 Anyone who acts in defence:
…
2 avoid[s] locating military objectives or positions within or near densely populated areas.

[emphasis in original]
In 2005, Switzerland withdrew its reservations to Articles 57 and 58 of the 1977 Additional Protocol I.
In 2010, in its Report on IHL and Current Armed Conflicts, Switzerland’s Federal Council stated:
Combatants in civilian attire who blend in with the civilian population, thereby deliberately placing civilians and civilian objects in danger, are in flagrant contradiction with the obligation that international law imposes on all parties to a conflict to take all feasible measures to ensure the protection of the persons and objects concerned.

[footnote in original omitted]