How to make a 'spoiler' post?

[BoloDigby]

Sorry but my forum noobishness means I can't figure out how to obscure my post with the 'spoiler' tag. Any direction would be helpful. I want to post a 'boss monster' sighting, but can't figure out the code.

[anon123]

Use the following code:

Your text goes here

[BoloDigby]

Use the following code:

Your text goes here

Thanks, I was trying html markup...