You should have read the BBcode Guide so that your guide isn't just a wall of text. I won't downvote it because it is pretty good though I disagree with some points.

Hi there after reading through your guide, I thought i'd leave some constructive criticism; while i agree with what you have said i agree with most of your suggestions however the bulky chunks of text are hard to read through. Simply paragraphing between each item or each time the point moves to something different will make this much easier to read. Just some food for thought for any future guides you write.