Yep! I told my parents to wear something "presentable" and "Comfy enough to fly back in. That meant khakis and a polo shirt for dad, my mom wore a nice sweater (it was winter) and a pair of dressy jeans. But we had parents/family/significant others attend in a suit and tie, clubbing dresses, cowboy boots, Harley shirts with leather vests, skirt suits and everything in between. So, take everyone else's advise into consideration. Comfy, suitable for weather, and appropriate next to your dashing newly minted Coastie.
We put HOURS into just our shoes for that one moment, and DAYS into making our graduation uniform look perfect. So take a few minutes and make sure you look good too