Hello!
I have a question about the BBCode button "sup".
Where can I change the default font size and the distance to the following text in which a sentence is written when I have selected "sup"?
~ Mrs. Chaos
You'd have to write your own CSS for that. The BBC just uses an HTML sup tag, which has default styling done by the browser.
Example:
sup {font-size: 1em. color: red;}