Related Rule
Practice Relating to Rule 65. Perfidy
Section G. Simulation of protected status by using the United Nations emblem or uniform
Germany’s Military Manual (1992) provides: “Grave breaches of international humanitarian law are in particular: … perfidious … use of recognized protective signs.” 
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, § 1209.
Germany’s Law Introducing the International Crimes Code (2002) punishes anyone who, in connection with an international or non-international armed conflict, “makes improper use … of the flag … or of the uniform … of the United Nations, thereby causing a person’s death or serious injury”. 
Germany, Law Introducing the International Crimes Code, 2002, Article 1, § 10(2).