HP Color LaserJet 4500 Printer series - Manual (Page 176)

176 PCL Commands
EN
PCL Commands
PCL printer commands instruct the printer which tasks to perform or
which fonts to use for specific print jobs.
PJL Commands
The HP Printer Job Language (PJL) provides control above PCL and
other printer languages. The four major functions provided by PJL
are:
● printer language switching
● job separation
● printer configuration
● status feedback from the host
PJL commands can be used to change printer default settings.