HP PCL/PJL reference - PCL 5 Comparison Guide

1-4 Printer Features ENWW
Note In Table 1-1, if the command value field parameters are not listed,
then all parameters are supported by printers that support that
command.
The value in parentheses following a command parameter identifies
the parameter value (for example, the parameter “Letter (2)” indicates
that the value field to select letter size in the Page Size command is
“2”).
Commands which are not supported (“ns”) by a printer are ignored.