So my mom is telling me she's never heard of such a thing, but I myself have gotten them in the mail for friends weddings. And my FMIL is on board (they are hosting the dinner). Our wedding is about 3.5 hours away and most guests know because they needed to book the night before as well as the night of the wedding to be able to come to the rehearsal. But anyway, we are planning to send formal invitations for the rehearsal dinner. Not fancy ones, from zazzle. But to let those people know a time, location and that they are invited with their guest, plus the restaurant has asked for entree choices in advance. I think mom is outdated and never dealt with a semi-destination wedding. Mom thinks we should just tell people word of mouth. Am I nuts?! Or is she ?