hmmm. so the "bugger words" at the end of, for example, http://www.ibiblio.org/apollo/listings/Colossus249/MAIN.agc.... are checksums - see http://books.google.cl/books?id=3fKzL0HfJp4C&pg=PA232...
anyone know the etymology? is it just a shortened form of "debugger"? is "bugger" not common slang in american english? or is this a joke?