BBCode BBCode provides a way to format your posts, whether you're adding an image, or just want to change the color of your text.
If you are making a post at a message board, you will see buttons you can click on to insert the various BBCodes into your post. If you are posting elsewhere, such as in your blog, adding a signature, or adding a message to your PM answering machine, you will need to either type the BBCodes in, or draft your post (without actually posting it) at a message board where you can use the buttons, and then copy that text over to wherever you want to use it.
Below are the codes you can use in message board posts, signatures, blog posts, and your PM answering machine: