This is also how we sent out our "announcements." On one side it stated that we were getting married, the date and location (no specifics, just the city,state). On the reverse side, it stated "please join us in celebration", date, time, location (specifics).
We hand delivered most of these and made sure to state that they were invited to the AHR. Even so, many of the guests were asking details about the wedding. I guess our the wording didn't give them the clue that they weren't invited to the wedding.