Arbortext IsoDraw > User's Reference > Palette Window Toolbox > Selecting > Marker > Generation
  
Generation
In order to draw a marker, select the Drawing of markers tool from the toolbox; the cursor becomes a marker cursor.
Click the point in the drawing area where the marker’s arrow tip is to be located. Then drag the marker as you would a line.
Markers cannot be changed with menu commands. However, they can be moved, changed in length and transformed like a line.