It is well known that the southern song style of counting rods, had different forms for the digits 4, 5 and 9 https://en.wikipedia.org/wiki/Counting_rods , however currently there is no way to represent such forms, a proposal to add them would only occupy five code points, since number four is identical both vertical and horizontally.
[http://upload.wikimedia.org/wikipedia/commons/thumb/e/ea/Yanghui_triangle.gif/200px-Yanghui_triangle.gif]<https://en.wikipedia.org/wiki/Counting_rods> Counting rods - Wikipedia, the free encyclopedia<https://en.wikipedia.org/wiki/Counting_rods> en.wikipedia.org Counting rods represent digits by the number of rods, and the perpendicular rod represents five. To avoid confusion, vertical and horizontal forms are alternately used.
