Normally, graduate school send the transcript to your undergraduate school to check the signs of the dean, the school office and the reference. Whether fake actions exist only depends on the reply of the person who serves for your undergraduate school as a document manager. In some conditions, graduate school contact your alumni. They may also compare your transcript with those of others. For example, you have deleted some required courses but your classmates didn't do so. Then they will contact one of them to make sure whether this course is required and whether your school permits students do such modifications. In this way, fake ranking information could also be checked out.