Related Rule
Germany
Practice relating to Rule 66. Non-Hostile Contacts between the Parties to the Conflict
Section D. Refusal to receive parlementaires
III. Military Manuals
Germany’s Military Manual (1992) provides: “The commander to whom a parlementaire is sent is not in all cases obliged to receive him.” 
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, § 226.