G76:

X - XEnd
Z - ZEnd
Q - Spring Passes. (optional)
P - Pitch
H - Depth of first pass
I  - Infeed angle
R - XStart (optional)
K - Z Start (optional)
L - Chamfer ( optional)
C - X Clearance
B - Depth Last Pass( Optional)
T - Taper (optional)
J - Minimum depth per pass