- Ck - set pen color to k
- S - set origin, increment for the pen
- U - set overall y-offset for the graph
- A, a - zero multiple line offset, increment offset
- G, H - move to first point, normal or hidden
- g, h - move to additional point, normal or visible
- s - push, then increment the pen position
There are several documents available explaining REC , including a read.me file in the rec subproject of each of the REC files.