Related Rule
Russian Federation
Practice Relating to Rule 67. Inviolability of Parlementaires
III. Military Manuals
Under the Russian Federation’s Military Manual (1990), it is a prohibited method of warfare “to kill parlementaires and persons accompanying them”. 
Russian Federation, Instructions on the Application of the Rules of International Humanitarian Law by the Armed Forces of the USSR, Appendix to Order of the USSR Defence Minister No. 75, 1990, § 5(d).
The Russian Federation’s Regulations on the Application of IHL (2001) states:
[P]arlementaires are persons authorized by their command to enter into communication with the enemy command and coming with a white flag. The parlementaire as well as persons who may accompany him (the trumpeter, bugler or drummer, the flag-bearer and the interpreter) have a right to inviolability. 
Russian Federation, Regulations on the Application of International Humanitarian Law by the Armed Forces of the Russian Federation, Ministry of Defence of the Russian Federation, Moscow, 8 August 2001, § 1; see also § 7 (prohibited methods of warfare) and § 67 (armistice and termination of combat operations).