Lexmark Optra Optra T User Manual page 50

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Proper loading helps prevent paper jams and ensure trouble-free
multipurpose feeder printing.
Do not remove any paper tray while a job is printing from the multi-
purpose feeder or is displayed on the operator panel. Doing so
Busy
may cause a paper jam.
Never add print materials to the multipurpose feeder while the
printer is printing from the multipurpose feeder. Doing so may cause
a paper jam.
Before loading paper, you need to know the recommended print
side of the paper you are using. This information is usually indicated
on the paper package.
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