Geessh . . . I hadn't thought about that. Our situations are slightly different. I'm going to send out Electronic (mostly) save the dates, that let them know there will be an ATR the following spring and a link to our website, and ask for an informal RSVP. Then I'll send out formal invites to all that RSVP'd yes (you find differing opinions on this . . . I may change my mind). Finally I will send out semi formal invites to the ATR.