I attended a wedding where the invitation invited you to a "wedding reception" and there was a separate small card enclosed inviting me to the ceremony. Kind of an odd reversal of what you usually hear about. But the wedding was at a hotel and the ceremony was in a small room (prob some type of exec meeting room) a couple floors up from the reception room and wouldn't have been able to hold everyone who was at the reception. The reception itself was a bit more informal that usual - no assigned seating, just buffet stations set up around the room and different-sized round and square tables for people to sit. There was a jazz band playing but not much room for dancing and most people didn't. I don't think the bride and groom danced. But it was a fun wedding, really.