We've all heard of the big book burnings that the german National Socialists staged. Those were the books on te so-called 'black list,' books that were 'bad influences on the german people.' There was another, very different list, the 'white list,' containing books that were 'suggested reading for the german people.'
When noted german author Erich Kästner (living in british exile) heard that his books had been placed on the white list, he wrote a letter to the german government demanding that his books rather be burned in the cleansing flames than be used for such smut. And so, his books were placed on the black list and burned.