Completely agreed with TEM. For instance, I've just finished reading A Practical Guide to Racism, which jokingly attempts to bluntly define each of "the nine major races: Hispanics, Blacks, Whites, Jews, Asians, Arabs, Indians (which includes 'dem 'Injuns'), Gypsies and Merpeople". As long as it's not rooted in hateful sentiments, there's nothing inherenly wrong with racial humour.