The Discworld Diaries are a series of themed diaries based on the Discworld novels by Terry Pratchett. Each one is based on an Ankh-Morpork institution, and has an opening section containing information about that institution written by Pratchett and Stephen Briggs. The diaries feature a great deal of background information, far more than could reasonably be put into the novels. However, some of this occasionally finds its way into the series proper - the concept of female assassins and the character of Miss Alice Band were two notable ideas that first appeared in the Assassins' Guild Yearbook.