How come sticking the url into the "link" button doesn't format it correctly?

right so I do need to make a small adjustment to the URL and Image part of the button guide. You have to click on the URL/image button again in order for it to create a closing bracket. When I made this I overlooked that step somehow.

This vaguely reminds me of html coding but with [] in stead of <>.

Which is why sometimes people will get the idea that they have to use html in the forums. I thought they looked very similar when I first learned BB code as well, but BB code is much more simple of course.