Ports are notated by rectangles overlapping the boundary of their owning blocks or properties (parts or ports) typed by the owning block.
Modeling a Port on a Property
The Port on Property symbol can only be drawn onto a Property symbol on a SysML Block diagram.
A Port is a specialized Property.
While the Port on Class symbol populates the appropriate property references when drawn, the Port on Property symbol does not, because it is an indirect reference.