HP 4 FAMILY - Manual (Page 163)

Note Table 4-3 lists the User Default Environment. This print
environment is stored in non-volatile RAM (NVRAM),
which allows it to be retained in the event of a power cycle
(except for the HP LaserJet 4L, 5L, and 6L printers, which
do not contain NVRAM). In earlier printers without PJL,
the feature settings contained in the User Default Environ-
ment were selectable through the control panel only. In
newer printers with PJL, these feature settings can be set
from either the control panel (if the printer has one) or
through PJL or both.
The User Default Environment is reset to the Factory De-
fault Environment upon a cold reset.
Print Environment 4-7