Wedding invitation wording?

So i have made my own invitations and searched for the right wording to use. I love how they have turned out. We actually had to do 2 sets, one for the private ceremony (and reception) and another for just the reception. My dilema is, on the reception invitations would it be improper to request an rsvp but not include a rsvp card? Our reception is very informal btw... its a backyard bash.