Related Rule
Practice Relating to Rule 22. The Principle of Precautions against the Effects of Attacks
Croatia’s Commanders’ Manual (1992) states:
To restrict civilian casualties and damage, the means of combat and weapons shall be adapted to the environment of the defence position … When the mission permits, appropriate information and warning shall be given of defence measures endangering civilian persons, so that they can behave accordingly in the event of combat action. 
Croatia, Basic Rules of the Law of Armed Conflicts – Commanders’ Manual, Republic of Croatia, Ministry of Defence, 1992, §§ 58 and 61.