Spoiler prefix and tag.
 

If you are discussing spoilers in a book, movie or television series (etc), please mark the thread as spoiling using the thread prefix when you create it. If there are certain parts of a post that are spoilers, please place spoiler tags around the content as described below. This way users who do not wish to know what happens can avoid the material.

How to use the spoiler tags:

[spoiler]Enter the information you want to hide here![/spoiler]

Example: