Wikipedia:Spoiler warning
From the Simple English Wikipedia, the free encyclopedia that anyone can change
A spoiler warning is information to tell people that some of the story is going be mentioned (like a film, game or book). A warning template is displayed on such articles because some people do not want to find out until they have watched, played or read whatever the thing is. Read below the template on the page at your own risk but the story will be spoiled on that subject.
If you are looking for the template, go to Template:Spoiler. If you want to put it into an article use this text: {{spoiler}}. You can also add this text to the end of the spoiler section: {{endspoiler}}.