IMDb Data Partner: The Writers Guild of America
The Writers Guild of America (WGA) has a well-defined process for determining credits on projects produced under its jurisdiction. These productions are generally USA-controlled live-action film and TV projects, produced either by studios or major independent producers. In 1999, the WGA began furnishing credits directly to IMDb. The absence of the WGA indicator on earlier credits should not be construed as a sign of unofficial status, merely a sign of age.
In general, the credits determination process works as follows:
If there is no source material (novel, play, article, etc.) and the same writers receive credit for both the story and screenplay, the credit is "written by".
The "story by" credit is used when the basic narrative structure was originally written with intent to be used for a movie (as opposed to a short story) and the actual screenplay had different authors. A shared "story by" credit is the minimum awarded to the author of an original screenplay.
If there was previously existing source material but the writer creates a substantially new and different story from the source, then the "screen story" (or "television story") credit is used.
Finally, the "screenplay by" (or "teleplay by") credit is used to denote the screenplay (teleplay) authorship if the story credit had to be separated as above.
In rare cases, "adaptation by" can be awarded to a writer who shapes the script without qualifying for one of the above credits.
There are other specialized credits used for television programs such as documentaries and audience participation shows.
The IMDb will not accept uncredited writers for titles with WGA-determined credits.
The WGA is also on the world wide web. Their address is http://www.wga.org/