Xerox Document Centre 255 LP Reference Manual page 32

The Machine Administrator will set up each tray to be Fully
Adjustable or Dedicated.
If the tray is Fully Adjustable, anyone can change the stock size,
type and color via a pop-up screen that appears when the paper tray
is opened then closed. This screen provides the option to confirm or
to change the paper settings.
When a Dedicated paper tray is opened, a pop-up screen will appear
on the User Interface identifying the stock that should be loaded in
that tray; however, it will not allow you to reprogram the settings.
Only the Machine Administrator can change the stock attributes for
a Dedicated paper tray.
The machine requires certain sheet orientation for network print
jobs. A message on the screen will notify you when the orientation
is not correct to support network printing.
NOTE To avoid undesired output results, every effort should be made to
ensure that the programmed stock settings match the actual tray
contents and all the stock in a tray is identical.
Page 3 - 4 Xerox Document Centre Reference Guide