German public administration follows the Grundsatz der Aktenmäßigkeit, the principle that every case is kept in a file. The Bundestag’s research service wrote in 2023 that proper file-keeping includes this duty. A paper by a federal and state working group on IT in administration, published by the Federal Archives, explains why. Only a complete file allows a full and legally secure reconstruction of a case. The documents serve as later proof of completeness, and they make a decision traceable and transparent. Lawyers and civil servants know the old maxim behind it. Quod non est in actis, non est in mundo. What is not in the file is not in the world.