From ATXHackerspace
If a vinyl cutter were to hypothetically support HPGL, here are the commands it should know about (according to HPGL Distiller)
IN // Initialize
PA // Plot Absolute
PD // Pen Down
PU // Pen Up
PG // Page Feed
PM // ??
PR // Plot Relative
!PG // ??
HPGL info
HPGL/2 info