I've always thought Karl Barth was Swiss Reformed active in the Confessing Church during the Nazi era. I'd expect to see him under Reformed rather than generic Protestant.
Wikipedia identifies him as a Swiss Reformed theologian, though it doesn't have a link for "Swiss Reformed" but rather for "Reformed theologian" so that would probably be OK too.
The other problem with this entry is using an apostrophe for the plural of Nazi. It should be Nazis.
We'll take a look at this. Addressing the denomination might open a can of worms so when and how it's changed is more tentative.As for the spelling of Nazis: that is something we can and will be able to fix.
