Spoiler

From Literawiki, the what to read wiki

A spoiler is a piece of information that, released too early, might spoil someones enjoyment of a book, movie, story, etc. For example, information about who-done-it spoils a mystery; information about who-ends-up-with-whom could spoil a romantic story; or who wins the battle and who dies could spoil an epic about a war between good and evil. Anything about plot twists or surprises could be a spoiler.

Spoiler notices or alerts are sometimes included in article before the potentially spoiling content in order to warn readers.

On the Literature Wiki, spoiler alerts are posted at in the text, before the spoiler. They look like

Read beyond the alert at your own risk.