Our venue only provides seating during the ceremony for 50 guests, the remainder of guests stand. (I know, every butt should have a seat BUT it was one of very few drawbacks about our venue - Fortunately the ceremony will be short and sweet). How should we have our ushers communicate this to guests as they arrive, specifically, how do we ensure seats are reserved for elderly guests, those in poor health, people with small children, etc? Or would it be best to reserve seats for those we know need one?