Suggested Edits stats there is a "controversial" edits section. But after looking at these edits I'm not so sure what is so "controversial" about them and why the system identifies them as such.
So what is the reason?
All of the edits in that list were approved by some users but rejected by others. It looks like what makes them controversial is that at least one user disagreed with the decision taken by others.
You can see this by clicking on the "approved" link which takes you to the page of the edit suggestion.