The SS-Sammellager Mecheln (Dossin barracks) opened its doors on 27 July 1942. Three non-Jewish secretaries from Mechelen were hired to help at the Aufnahme. The other employees of the camp administration were recruited among the young Jewish girls who arrived at the SS-Sammellager on 27 July. Work at the Aufnahme was divided into two sections : the administration of the camp led by SS-Hauptscharführer Max Boden and the confiscation of Jewish property led by representative of the Brüsseler Treuhandgesellschaft Erich Crull. The employees at the Aufnahme, mostly inmates themselves, worked day and night to register all Jewish prisoners arriving at the SS-Sammellager. They also drafted the deportation lists, distributed cardboard identification tags, physically searched newly arrived detainees and completed confiscation forms. The Aufnahme continued to operate until the liberation of the SS-Sammellager (Dossin barracks) on 4 September 1944.

In the night of 3 on 4 September 1944 Mechelen was liberated by British forces. A series of 3,065 envelopes was found at the Aufnahme (camp administration) at the SS-Sammellager Mecheln (Dossin barracks). The envelopes contained personal documents and a few items, which had been confiscated from Jewish detainees upon their arrival at the barracks in 1943-1944. Most of the confiscated documents belonged to detainees who had been deported via transports XX until XXVI from the Dossin barracks to Auschwitz-Birkenau. However, several dozen of the envelopes contained documents of detainees who had passed away at the Dossin barracks or had died at the Breendonk camp for political prisoners, detainees who had been released from the Dossin barracks or who were deported to smaller camps such as Buchenwald and Ravensbrück. The series was post-war consecutively administered by the Belgian Ministry of Reconstruction and its successor, the Service for War Victims (today the Directorate-General War Victims, subdivision of the National Archives of Belgium). In 2003, the Jewish Community Indemnification Commission (Buysse Commission II) advised that the series would be stored at the Jewish Museum of Deportation and Resistance, after which the envelopes were physically transferred to the JMDR. Its successor, Kazerne Dossin, has digitised the complete series.

Directorate-General War Victims - National Archives of Belgium, 2003