International Committee of the Red Cross
After November 1943, the ICRC could send parcels to concentration camp detainees with known names and locations. Because the notices of receipt for these parcels were often signed by other inmates, the ICRC managed to register the identities of about 105,000 detainees in the concentration camps and delivered about 1.1 million parcels, mostly to the camps Dachau, Buchenwald, Ravensbrück, and Sachsenhausen.