There are a couple of cases where this is necessary on a day-to-day basis.
The first one that comes to mind is where the person handling receiving has to accommodate a change in an EAN or UPC. Some companies change these codes with frightening frequency. (Frito-Lay comes immediately to mind.)
The second is a case where an item with a price tag is not ringing up. In the interest of keeping the line moving it is reasonable to create a part for the sale and move it to the right part later.
I am open to changing this but those are the specific cases I had in mind.