Related Rule
Practice Relating to Rule 22. The Principle of Precautions against the Effects of Attacks
Sweden’s IHL Manual (1991) refers to the obligation enshrined in Article 58(c) of the 1977 Additional Protocol I to “take other precautionary measures for protecting the civilian population, civilian persons and civilian property”. It notes that: “These can include a number of different measures such as the erection of shelters, distribution of information and warnings, direction of traffic, guarding of civilian property and so on.” 
Sweden, International Humanitarian Law in Armed Conflict, with reference to the Swedish Total Defence System, Swedish Ministry of Defence, January 1991, Section, p. 74.