HP LaserJet 4100 HP PCL/PJL reference (PCL 5 Printer Language) - Technical Ref - Page 74

Note If you specify P1 and P2 beyond the PCL Picture Frame, your drawing is scaled with respect to those locations; however, only the portion of the drawing fitting within the effective window is drawn. The specified P1/P2 percentages are converted to the equivalent plotter unit coordinates. If the coordinate system orientation subsequently changes (for example, by sending an RO command), the plotter unit position is maintained with respect to the new orientation. If an IP command without parameters is executed after the axes have been rotated with the RO command, P1 and P2 locations change to reflect the rotation. The locations of P1 and P2 interact with the following commands: Table 19-13 Commands Affected by P1/P2 Command Group IW, Input Window The Configuration/Status Group RO, Rotate Coordinate System SC, Scale FT, Fill Type The Line and Fill Attributes Group LT, Line Type PW, Pen Width WU, Pen Width Unit Selection DR, Relative Direction The Character Group LB, Label SR, Relative Character Size An IR command remains in effect until another IR command is executed, an IP command is executed, or the printer is initialized. 19-28 The Configuration and Status Group EN