Yes, the white coat ceremony is part of orientation before the first real day of med school. Not every school has a white coat ceremony. Basically, we line up in alphabetical order, and 11 or 12 of us walk up onto the stage w/our coat in over our arm, had it to the professor/administrator standing at our "spot" on the stage, and they help us to put on our white coat. Our names are called as we walk onto the stage, people clap, take pictures, hoot and holler, and as we come off the stage, we get a DO pin as well as a handshake from the Dean while our picture is taken with him. Since white coats are part of our dress code, they make a big deal out of the white coat ceremony. It was really nice, and afterwards, they have a lunch and mini-orientation at the school for any friends/family that have come with you.
You get the invitation to the white coat ceremony sometime in July I believe, and they just want a head count of how many people you intend to bring to the ceremony and then lunch. The ceremony is deemed mandatory.
I hope that helps