If you have a Das Keyboard Model S Ultimate, it’s likely that one day you will no longer be able to resist the temptation of disassembling its keycaps.
You might be surprised to discover that not all the keycaps are the same. If you look inside the keycaps, you will see letters and numbers. Notice them, and use this map. (R4 are the keycaps with only numbers inside.)
Now leave me alone :-)