In the Netherlands the position of the sails can be used as a means of communication to display joy or mourning . These sail positions are generally used by the miller to show for example a birth , marriage or death within his family or circle of friends but may occasionally also be used to show mourning at national events , for example the death of Prince Friso and during the day of national mourning for victims of the Malaysia Airlines Flight 17
Malaysia Airlines Flight 17
Malaysia Airlines Flight 17
Windmill sail