Actually, I didn't have a particular World War II category in mind to add to the Holocaust category because I'm clueless about where to put it. Although, of course, most of the Holocaust activities occurred in Germany, there were several other countries that were also heavily involved in it - Czechoslavakia, Poland, and Russia had ghettos and concentration camps, Holland and Hungary had ghettos, there were also victims and survivors in France, and Germany's allies - Italy and even Japan - had victims, survivors, and heroes. In addition, England, Canada, United States, Australia, South Africa, Brazil, Uruguay, and Argentina were places where survivors emigrated.
Maybe it should be independent of any one country and just be immediately under the main World War II category. I'll put it wherever you think it belongs - you'd know that far better than I would!