German Federal Patent Court, the German court with exclusive jurisdiction over challenges to the validity of German patents, known as nullity actions. Appeal from the Bundespatentgericht is to the German Supreme Court or Bundesgerichthof. In a peculiarity of German procedure, the question of infringement of a German patent is held in special branches of the Landesgericht or Federal State Courts, with appeal to the Oberlandesgericht and then to the Bundesgerichthof so that patent procedure is effectively divided into two separate but related cases.