The "Markers" panel allows you to add markers to the positions: start, intermediate and end of a line or path.
The three buttons/positions, at the top of the panel, show the current status of the markers at start, intermediate and end of a selected element.
By clicking on one of these buttons, the panel will show the properties of the marker and the library of available markers.
The colors associated with the selected marker are listed below the three buttons; click on one of them to modify the current one.
Markers are assigned by reference. The first button below the colors allows you to duplicate the current marker, locking its reference. The second button allows you to edit the marker on an isolated layer.
The first field indicates the locked name/id of the marker.
The next drop-down menu shows how the marker will be drawn, i.e. whether it will use the line thickness as a scale parameter or use its original dimensions.
The next two fields indicate a displacement distance in X and Y (offset) from the original position.
The following parameters allow you to set a custom marker size.
The next drop-down menu allows you to define how direct the assigned marker.
The last field indicates a possible rotation to be assigned to the marker.