HP Color LaserJet 5500 Technical Reference Manual page 50

Comments:
5-4 Job Separation Commands
page of this job reaches the output bin. The variable
"display text" can be any combination of printable
characters and spaces or horizontal tabs, with a
maximum of 80 characters. The actual number of
characters displayed depends on the printer. The display
limit can be determined by sending an INFO CONFIG
command to the printer. The printer will return
DISPLAY LINES = value and DISPLAY CHARACTER
SIZE = value as part of the response.
Note
For HP LaserJet 4PJ, 4V, 4MV, 5Si, 5SiMx, 5Si Mopier
printers, if the LANG variable is set to Japanese, messages
are displayed using the JIS X0201-76 character set.
For the LaserJet 4000 printer, if LANG is set to POLISH,
CZECH, or HUNGARIAN, messages are displayed using
the Latin 2 (ISO 8859/2) character set. If LANG is
RUSSIAN, messages are displayed using Cyrillic (ISO
8859/51). For LANG=TURKISH, the display is in Latin 5
(ISO 8859/9).
When a JOB command is received, the printer does not
recognize the UEL command as a PJL job boundary until an
EOJ command is received. UEL commands within a PJL
JOB/EOJ command pair are treated as printer language
resets; they default the print environment to the PJL Current
Environment settings, instead of the User Default
Environment.
If your application has status readback capabilities, you can
monitor the job status using the USTATUS command with
the JOB option. If job status is enabled and the printer
receives a JOB command, it returns a job status message.
Note
Resetting the page count associated with unsolicited page
status affects only future pages. Pages already processed,
but not yet printed, are not affected.