PJL is the abbreviation for Printer Job Language. It is a method of printer control at the job level developed by Hewlett-Packard. The instructions for printers (e.g. language selection, paper size, selection of output tray, etc.) are prefixed to the actual print jobs in the form of so-called PJL commands. PJL commands apply to the entire job unless an instruction is changed within the print job via the printer language used. In this case a PJL command is valid only until this command is executed. The original standard from Hewlett-Packard has been extended by many printer manufacturers themselves, so that there is no compatibility when calling newer functions, e.g. the PJL command for stapling pages of a print job.