This is a handy enhancement that will speed up the selection of serial numbers in GP. Prior to GP 2013 you had to individually select serial numbers one at a time and insert them into the selected area on various screens in GP. In GP 2013 you can select ranges or several individual numbers at once and then insert them into the selected area.
This is an example of what available serial numbers look like, showing several selected at once:
This is a PowerPoint from Microsoft that explains this functionality: GP2013 FOD Multi-Select Serial Numbers
This is a quick video I created to show this in action.