Some references have special arrows, these are modelled also inside the style module. All arrow decorators are part of the package at.ac.tuwien.auto.modelua.papyrus.opcua.diagram.style.decorations and inherit the class PolygonDecoration.

The Tip is modelled as a PointList, note the last element links automatically to the first point. The tip is by default filled black, so if the tip should be white, that has to be set. For an example check out the HasSubtypeDecorator.java decorator