"Opening credits, in a television program, motion picture or videogame, are shown at the beginning of a show and list the most important members of the production. They are usually shown as text superimposed on a blank screen or static pictures, or sometimes on top of action in the show. Some opening credits are built around animation or production numbers of some sort (such as the James Bond films). Opening credits usually mention the major actors, guest stars, producers and director, as opposed to closing credits which lists the entire production crew." Source and further information: http://en.wikipedia.org/wiki/Motion_picture_credits For this reason, since Beverly D'Angelo could not be considered a major actor or a guest star of the movie, she was not credited. Here the list of the movies where she was uncredited: Summer Catch (2001) (uncredited) .... Lusty House Mother Divorce: A Contemporary Western (1998) (uncredited) .... Linda The Switch (1993) (TV) (uncredited) .... Dee Pacific Heights (1990) (uncredited) .... Ann Miller Source and further information: http://www.imdb.com/name/nm0000350/ Further information: http://en.wikipedia.org/wiki/Beverly_D'Angelo Possibly the actors themselves could decide to stay uncredited in some cases, as they know that they don't have a very important role in the movie, so that people don't go to see that movie just to see them and be disappointed.