My fiance and I are having a very small wedding. We're just going to have immediate family, our grandparents, and mutual friends at the ceremony and reception, and most of our friends will be in our wedding party (we each have three attendants). Everyone already knows about the wedding and that we're keeping it small...I think we'll have about 19 people in the "audience." My question is, do we HAVE to send out invitations, or can we just make sure everyone knows where to be and when (via e-mails, phone calls, or talking to them)? Is it tacky to not send invitations?