How do you do a spoiler?

[Trip]

Could someone do me a favor and remind me how to make a spoiler?

 

[Heyden]

[spoiler]insert[/spoiler]

 

[Trip]

[spoiler]insert[/spoiler]

Thank you!

 

[Aquari]

Spoiler: title

content [/SPOILER ]

 

[AnimalCrossingPerson]

And before you come up with a follow-up question, a single space as the title will get you a thin spoiler.

[SPOILER= ]Hello![/SPOILER]

Spoiler:

Hello!