A Packing Unit is a moveable location such as a box, pallet, or crate. The objects in a Packing Unit will have the same location as the Packing Unit.
You can move multiple objects at once if they are all in a Packing Unit.
You can check which objects are in a Packing Unit, by clicking the buttons on the Objects tab of the Packing Unit Identification window.
A Marine Department packing unit showing that the Usual Contents of this tub is a Hector's Dolphin skeleton.