BBCode? I'm guessing that's the same thing as what is referred to as Forum Code?
For example, to make something
bold - you can add
tags around the words you want to have bolded - without the space after the 'b'.
There is a link to the left of the Message Box labeled "Forum Code" which explains how it works. It is the same coding that is generally used in other boards. With the forum codes, it is possible to do a decent amount of formatting.
As far as true HTML - this is one feature that will not be turned on. There is too much potential risk of people abusing it and causing problems through scripting and other various things.