In the German dubbed version Otto and Gretchen Mannkusser are from Denmark and not from Germany, they speak with a Danish accent. In this episode Otto's nephew Willy (a typically German name) from Germany visits him. When Francis tries to talk with Willy (his name in the German dubbed version is Björn), it is a little bit confusing for German viewers that Francis has a German dictionary and not a Danish one.
The keyboard Willy plays is branded "Sydnor" -- the chief music editor of the series is Charles Sydnor. This is also referenced in Season 5, Episode 16 (Malcolm Visits College).