How to fill Pattern field

f Draws a line.
c Draws a filled circle.
< Turn left.
> Turn right.
t Turn left or right, at random.
? Turn left or right or not at all, at random.
n Step forward with no drawing.
- Step backward with no drawing.
d Duplicate - create a child in my direction.
b Branch - 50% chance of creating a child
m Mirror - 50% chance direction inverted.