The International Tracing Service (International Tracing Service), based in Bad Arolsen, includes the archives of the Nazi concentration camps and the S.T.O. This service makes it possible, among other things, to formulate tracing requests for prisoners who disappeared during deportation.

The management of these archives was originally assigned to the International Committee of the Red Cross.

For some thirty years these archives were no longer available for consultation. After years of struggle, particularly on the part of associations of deportees, a decision to reopen the archives to the public and historians was signed on 24 July 2006 by the International Commission for International Research Service (CISIR). We can only acclaim this decision. 

Beyond its original humanitarian mission, the S.I.R. is now dedicated to be a documentation centre, whose collection contains 47 million documents concerning more than 17.5 million people.