@ucbalumnus You’re right, and this BDH article provides more info: https://www.browndailyherald.com/2012/09/05/shopping-period-tradition-thrives-among-students/ The main thing about shopping period is that you’re able to attend as many classes as you want without limit, whereas add/drop would likely limit you to a certain number of courses, though you can’t register for more than 5 course at any time at Brown either.