You can be excused, but don't do again. If you continue to do it, then you have to suffer. Once or twice, you may be excused. But if you continue to do that, you must be punished: Revision history
Diff selection: Mark the radio buttons of the revisions to compare and hit enter or the button at the bottom.
Legend: (cur) = difference with latest revision, (prev) = difference with preceding revision, m = minor edit.