How do I make a category in a post???

[Tr1sK3Li0n]

I've seen it used all the time but i havnt a clue how to do it...

here's an example:

here are my Mario cards:

mario cards (click to view)

Luigi cards (click to view)

Yoshi (click to view)[/u]

[KuroKibo]

[spoiler=The title here]The content here[/spoiler]

It'll come up as

[spoiler=The title here]The content here

 

For underlines, just add:

[spoiler=[u]The title here[/u]]The content here[/spoiler]

It'll come up as

[spoiler=[u]The title here[/u]]The content here

 

[Tr1sK3Li0n]

Thanks, it's been driving me mad trying to figure it out =]