HP LaserJet 4100 HP PCL/PJL reference (PCL 5 Printer Language) - Technical Ref - Page 307

Figure 23-33Label Origin Positioning Each time an LO command is sent, the Carriage Return point is updated to the location the pen was in when the LO command was received. The current pen location (but not the Carriage Return point) is updated after each character is drawn and the pen automatically moves to the next character origin. If you want to return a pen to its previous location prior to the next label command, you can send a Carriage Return after the label text but before the label terminator. When you embed Carriage Return characters in a label, each portion of the label is positioned according to the label origin, just as if they were written as separate label commands. An LO command remains in effect until another LO command is executed, or the printer is initialized or set to default conditions. Table 23-34 Example: Using the LO Command ECE EC%0B IN; Reset the printer. Enter HP-GL/2 mode. Initialize HP-GL/2 mode. SP1;SC-4000,4000, -5000,5000; Select pen number 1; specify scaling by assigning (-4000,-5000) to P1 and (4000,5000) to P2. EN LO, Label Origin 23-63