If you've realized; You can only type plane text in the "Quick reply" slot.
But what's if you want to add some Formating?
I found that the easiest way to do this is to click "Post reply" while the message is still empty then you have the full format for creating Posts with full-fledged formating.
Then you can add all of these ;D !
And even shorter than that is, just to press ALT+S.