In this and other episodes, the German word for "Missing" is spelled "Vermisst" on 1986 posters and in newspaper headlines. Before the 1996 spelling reform, however, the word was spelled "Vermißt" in Germany, unless a non-German typewriter was used or the word was written in capitals only.
In 1986, Ulrich is playing a game on his Commodore 64C in his bedroom. The Commodore 64C was not released until 1987. To be correct, the creators of the series should have used the "breadbin" version of the commodore 64.