When it comes to smart casual for men, go for casual trousers such as chinos or suit pants. In summer, you could even wear shorts. They can accompany their trousers with a long-sleeved shirt, and an optional jacket and tie. If you must wear denim, go for the stylish dark blue, tailored type.
A couple of tips: If the brides parents are hosting, its customary to leave off the brides last name. But in the case of a bride having a different last name than her parents, her full name should be used. If the grooms parents are involved, the brides last name should be included. In its simplest form, this is the standard wording template.
The formal dress code is located somewhere between cocktail and black tie. For the ladies this dress code requires a short or long formal dress, a pantsuit, or dressy separates. For men, a dark suit, white shirt, and conservative tie is appropriate. Men can opt to wear a tuxedo if they wish, as the formal dress code is really another way to describe black tie optional.