Related Rule
United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 55. Access for Humanitarian Relief to Civilians in Need
Section D. Right of the civilian population in need to receive humanitarian relief
The UK Military Manual (1958) provides:
Every opportunity must be given to protected persons to apply to the Protecting Powers, the International Committee of the Red Cross, the local national Red Cross (or equivalent) society or any other organisation that may assist them. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 40.