The AllowLinkControlPoint property indicates the control points of the link, the user can use to customize the link's path. The property is applied to all links (unless the AllowControlPoint property indicates a different value). For instance, exStartControlPoint | exEndControlPoint specifies that the user can change only the start/end position of the link. The exStartControlPoint and exEndControlPoint points are marked with black squares and defines the link's control points to change the link's start (Link.StartPos property) and end (Link.EndPos property) position. The exControlPoint points are marked black circles and defines the corners of the link's path. You can remove a exControlPoint points by dragging to another, so intermediate exControlPoint points are removed. You can move all control points of the link at once, if SHIFT key is pressed. The exMiddleControlPoint points are marked with gray circles, and are displayed between two exControlPoint points, to let the use add new exControlPoint points, to redefine the link's path. The LayoutStartChanging(exLinkControlPoint) / LayoutEndChanging(exLinkControlPoint) events as soon as user starts / ends changing the link's control points

The CustomPath property specifies the link's custom path, as a string of x,y proportions separated by comma. The CustomPath property contains the proportions of link's control-points, as a "x,y,x,y,x,y,...". The x, y are proportions of link's control-points relative to the start/end points of the link. The 0,0 indicates the link's start point, while 1,1 indicates the link's end point. For instance, "0.5,0,0.5,1" defines the link to go from start (0,0) to (0.5,0), then (0.5,1), and finally to the end (1,1)