[Rechtsstaat]

On some keyboard layouts, pressing the quote mark starts a modifyer and then depending on the layout the following character is combined with the quote mark. Most English layouts don't include ś in this, but some Eastern European (?) languages use that character more often and so include them in this modifyer shortcut.

[JohnFen]

I honestly didn't expect the explanation of that to be as interesting as it is! I had no idea...