You changed the function to take an int instead of a double, and it ended up really screwing up the tests. You're supposed to return true if n is even, but your code really broke this kata.

Oh, and footnote 8 claims the Swiss are particularly fond of watchmaking, bit twiddling, the Basic Latin Unicode block, and Gruyère cheese. Weird mix. I don't know if any of that is true though.

I don't know. I guess you'll have to ask the Swiss Bundesamt für Organisation. They chose these letters back in 1964: D for Deutsch, F for Français, I for Italiano, and (by accident, they say) K for Rumantsch.