Related Rule
Practice Relating to Rule 36. Demilitarized Zones
Section A. Establishment of demilitarized zones
Germany’s Military Manual (1992) states:
The prerequisites for establishing [a demilitarized zone] are equal to those applying to non-defended localities (Article 59 para. 2, 60 para. 3 of the 1977 Additional Protocol I). Demilitarized zones are created by an agreement concluded between the parties to the conflict either in peacetime or in case of conflict. It is prohibited for each party to the conflict to attack or occupy such zones (Article 60 para 1 of the 1977 Additional Protocol I). 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, August 1992, § 461.