Samsung ML--6100 - Manual (Page 50)

3. 11 Print Media Information
Using Rear Output Tray
If you open the rear output tray, the printed paper is placed on the tray
with the printed side facing up. If you experience paper jams, especially
when you load paper, envelopes, or other special media into the MP tray,
use the rear output tray.
1. To use the rear output tray, open the rear cover. The cover functions as
an output tray.
2. Pull the extender to extend the output tray to its full-length position
to hold longer paper.