Reception only invites-rude to list registry?

My fiance and I are planning to have an outdoor wedding and indoor reception all at the same location. However if the weather is bad we can hold it indoors in one half of the building but that side only seats 200 people (entire building seats 400 which we'll have the entire building for the reception). We are planning to invite 300 people total so we have decided to keep the ceremony to family members (immediate, grandparents, aunts/uncles, etc.

and allowing bridal party and groomsmen to bring their SO). I obviously have no way of predicting the weather or how many people will RSVP that they are coming until RSVPs start coming back thus the idea of limited ceremony guests.

On the reception only invites, is it rude to list where we are registered in case they want to bring a gift even though they aren't invited to the ceremony? I truly wish we could invite everyone to the ceremony but with potential seating issues if we have to move indoors, I didn't want to worry about last minute cramming guests in like sardines.