I mention in the book that bona fide white trash is proud to be exactly that. But call someone white trash who isn't, or someone who is too ignorant to know that they are and look out! It's like throwing gasoline on an open flame; you better watch out.
I also include in the book a handy dandy checklist, just in case you're not quite sure whether someone you know is white trash. Little clues like a person's manner of dress, of speech, whether that person seems aware of any type of etiquette…even a person's shopping and grooming habits all clue one in to whether a subject is true white trash.
These are things one truly must know, especially here in the South, Nowhere else in the country is one's status – or the perception of one's status - quite as important as it is here.