The Allgemeines Deutsches Kommersbuch (ADK) or Lahrer Kommersbuch is the most popular commercium book in Germany. It was first published in 1858 and came up to its 162nd edition in 2004. It is the German equivalent of the Flemish studentencodex.
s:de:Allgemeines Deutsches Kommersbuch in the German Wikisource project.