From Martin, I know more thing about Swiss keyboard.
To explain the following, we have to start from the languages using in Swiss. Swiss has several areas – French area, German area, and Italian area.
Worb, the place I am working at belongs to German area. So the frist official language is German. While, the French area also has people who speak German, but with different habits.
This also reflect to the keyboard using.
Let’s use 
as the sample to explain how different people use this key.
There are 5 characters in this key. How to use them?
For the Swiss German area poeople, they will use the right 2 characters plus the middle one. I.e 
.
Key itself alone: character “ü”
Shift + key: character “è”
Alt Gr + key: character “[”
For the Swiss French area poeople, they will use the left 2 characters plus the middle one. I.e 
.
Key itself alone: character “è”
Shift + key: character “ü”
Alt Gr + key: character “[”
From the OS’s keyboard settings, you also can see below:
.
“Deutsh” means “German”.
So the upper one is for the Swiss German, the lower one is for Swiss French while speak German.