Originally Posted by Critic

tornado163, most hubs and larger airports assign different banks of kiosks/desks for different functions. EWR has separate areas designated for UA.com Bag Drop, Economy Checkin, and PA checkin. Essentially all of the desks can perform all of the same functions, but pax are self-selecting their line based on their needs. (A kettle could use the normal checkin line to check a bag, but they couldn't use the bag drop line if they need to see an agent about reaccommodation, for example.) All of the kiosks are running the same interface, and provide the same options.

Outstations forgo the dedicated bag drop line - that may be why you haven't encountered it. FYI, however, even if you are prompted to use the kiosk to find your PNR, you can skip the BP reprint by tapping Finish.