All arcs are drawn so that their geometry extends beyond their endpoints by one-half of their width. This property can be set or reset with the Toggle End Extension command (in menu Edit / Arc ). It may also be controlled by checking the appropriate box in the Object Properties... dialog.

Individual ends of an arc may be controlled with the Toggle Head-Skip and Toggle Tail-Skip commands, or by checking the "Ignore head" and "Ignore tail" boxes in the Object Properties... dialog. When an end has been ignored, the property associated with it does not occur. This means that directional arcs have their arrowhead omitted (when the head is ignored); negated arcs do not have the bubble drawn (when the tail is ignored); and arcs with their ends not extended have that end extended.