Private and Public Writing

When I think of public writing I think of this in the newspaper, magazines, and books.  Public seems more formal but doesn't always have to be.  Usually though it follows the rules of grammar and spelling and would be edited by someone else.  Private writing to me is more like something written that maybe only one other person would see.  A diary, letter, or journal would fit into this.  Now Bridget Jones's Diary was written to be read by lots of people so it is public.  However it was written in a style that is private.  It is very informal by using abbreviations, swear words, and incomplete sentences.  The readers get a glimpse into a private life filled with neurotic thoughts and behaviors that one would never reveal to the public.