The marking tool can be held above or below the pivot point giving you more options for the angle the marking tool is presented to the work piece.
To change from the over to under positions remove the pivot bolt and flip the body 180 degrees.
Re position the threaded dowel and insert the brass spacer before the thumbscrew (or store it in the hole provided in the body if it’s not needed).
In this image the big boy on the left is holding a pencil above the pivot point.The big boy on the right is holding a metal scribe below the pivot point.