Revision history of "File:Click the More link next to the forum you want to delete, then chose the Delete Forum option from the drop-down menu. You can also click Forum Settings next to the forum you want to delete..png"
From EdTech Help
Diff selection: Mark the radio boxes 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.