First three norwegian cities I looked up was given the wrong name. (Plesund (should be Ålesund), Bodi (Bodø) and Tdnsberg (Tønsberg)). So, I think it is safe to say that there are encoding issues in the data set.
Looking at the SQL file, "Zürich" is listed as "Zdrich", Munich is only shown as "Munich" without the German name "München" anywhere, and Cologne is listed as "Cologne" with the wrong "Koln" as alternative name.
Doesn't look like a reliable data source.
It's strange, I can't really understand how these accents can get mangled as these particular single letters.
I think I also have seen such character set corruptions before, but I can't remember how exactly you can get these particular corruptions.
We'd love to fix all those issues -- maybe with some help from the community :)
The goal is definitely to turn this into a more and more reliable data source every day.
The complete build process is described in "SOURCE.md". That's where we got these encoding issues from -- right from the source material. Maybe we didn't open or parse the source material correctly. But we were not able to get them without the encoding errors.
We'll love to fix all these issues :)