You register at places (target, babies r us, Walmart etc) of the items you would like for your baby so ppl know what to get you. It is very helpful for the big items (
pack n play, stroller, crib etc) as those are the items you will pry be most picky on as far as style and brand. Also jumpers and other higher priced items. I never put specific clothes on mine other than making a point to show I want plain white onsies and diapers!