So we have decided to save money on stamps/envelopes we are only doing online RSVPs - our family will definitely be okay with it. It will be online through our website with The Knot and I have it set so that only people on the guest list can RSVP. Even though I'm doing that, should I still include the ____ seats saved in your honor on the card with the RSVP info? They can't technically RSVP someone who wasn't invited but maybe this will deter people from bringing someone extra anyway?