HP and 8150 MFP manual Printing Tasks 107, Job Separator, Stacker

Chapter 2 Printing Tasks		107
Job Separator	Print jobs are automatically sent one job per bin to the first empty
	bin beginning at the top bin. Non-empty bins are skipped. If all
	bins have paper, the job will be sent to the first non-full bin
	starting at the top. If a bin becomes full, the system will stop until
	paper is removed from that bin. Delivery then resumes in the
	same bin.
Stacker	This mode stacks the printed output from the lowest bin to the
	top, regardless of job boundaries. This mode of operation takes
	advantage of the total capacity of the mailbox bins. The device is
	seen by the software as one logical bin.

Selecting the Output Bin