You can use BBCode, but I don't really think it's needed.
You type this: [ SPOILER ] <your text here> [ /SPOILER ] -> Obviously you don't put spaces between the '[' and the 'spoiler' word. The place I said to you put your text in, you write anything you want, and it should appear as a spoiler. If your spoiler breaks, I think then it may be because you didn't use BBCode. So then try using it.
How to make spoiler names: instead of just making '[ spoiler ]', you do this: [ spoiler=<spoiler title> ]
Code:
To make a spoiler without a title/name: [spoiler]<text>[/spoiler]
Code:
To make a spoiler with a title/name: [spoiler=<title>]<text>[/spoiler]
Spoiler without a title/name example:
Hello, world.
What I did on the message above was: [ spoiler ] Hello, world. [ /spoiler ]
Spoiler with a title/name example:
This is a sample spoiler.
What I did on the message above was: [ spoiler=Sample Spoiler ] This is a sample spoiler. [/spoiler]
I recommend using BBCode.
I hope this helped you. If you didn't understand something, just tell me and I'll try to explain it better.
Note: You may be asking yourself how I made the "code" thing. To do it it's the same as the spoiler, but instead writing in 'spoiler', you write 'code'. e.g [ code ] What a beautiful day! [ /code ] -> It's simple like that.