Dell 5310n - Workgroup Laser Printer B/W Service Manual page 390

Place the support unit on top of any previously installed drawers, or the table or printer cabinet where you
2.
plan to use the printer.
The tab (A), round peg (B), and square holes (C) on top of any drawer help you position the support unit so
the edges are aligned properly. Make sure the support unit is securely in place.
Attach another optional drawer, a duplex unit, or the printer.
3.
You can attach a label to the trays to indicate the tray number.
Service Manual
A-2
A B C