However unlike fan fiction, 'overviews' summarizing their story, written early in the writing process, were 'approved' by Fox, who in turn may or may not have sought approval from Whedon (or his office).
To date, unlike traditional fan fiction, only one cease and desist letter is known to have been issued against RPF: FanDomination.Net received this letter on March 17, 2003 from a representative of one of the members of the New York Yankees baseball team.
However, unlike fan fiction, overviews summarizing their story, written early in the writing process, were approved by both Fox and Joss Whedon (or his office), and the books were therefore later published as official Buffy merchandise.
Unlike regular fan fiction, which generally remains within the boundaries of the canon set out by the author, alternative universe fiction writers like to explore the possibilities of pivotal changes made to characters' history, motivations or environment.