Xerox 4213 Programmer's Reference Manual page 80

XES COMMAND LANGUAGE MODE
Setting independent margins
2-42
Figure 2-6. Measuring a landscape page
The Margin Top, Margin Bottom, Margin Left, and Margin Right
commands allow you to set or change one or more margins on a
page without affecting other margins selected using the default
margins or the regular margin commands.
If margins have been defined with the Margins command and
then an independent Margins command is entered, the printer
continues to use the measurements in the Margins command for
all other settings. If no other margins have been set, the printer
uses the defaults for the other settings.
The same rules that apply to the Margins command also apply to
the commands for independent margins.
XEROX 4213 LASER PRINTER PROGRAMMER REFERENCE