Wikipedia is an attempt to write an encyclopedia. When art, be it books, music, visual art, computer games, or film, is discussed, it is in the attempt to provide a full summary of that creative work and its place in the greater sphere of human activity. To fulfill this task, it may be necessary to discuss the plot of fictional works in their entirety. Many books and films, however, lose some of their dramatic impact if the details of the plot are known before they are seen, particularly films with dramatic plot "twists" such as The Crying Game, The Wizard of Oz, and The Sixth Sense.
It is traditional netiquette for this discussion to be surrounded with warnings of "spoilers". Because of this, and because not everyone coming to the site immediately recognizes Wikipedia as an encyclopedia, please attach a warning text and link after the definition paragraph of an article that contains spoilers.
The standard warning text is below in raw form for quick copy-paste:
Readers should assume that any articles relating to narratives (novels, movies, adventure games, etc.) in the Wikipedia may contain details of the plot, and if they find that it disrupts their enjoyment of the story they should avoid reading such articles before experiencing the work. This may be true even for pages that do not include a spoiler warning. If you are working on such articles, feel free to include spoilers wherever appropriate.
Remember, a good encyclopedia article may contain spoilers, but ideally it should also contain much that cannot be seen from simply reading the book or seeing the film in question.
See also: Wikipedia:Policies and guidelines