It was appropriate that I found this coin in "Ancient Chinese Secret" because the coin itself seems to have some secret codes inscribed on it. I assume that the "Proving Trail" mentioned on this coin (which the German inscription calls a "Lehrpfad" or "Teaching Trail") is some kind of place for cachers to learn the art of caching, including solving codes and puzzles.
There's a piece of paper written in Hungarian in the bag with the coin; I'll see if I can find somebody to help me translate it!
Meanwhile I will move it a long distance soon.