I am having an information insert in my invitation to let guests know the ceremony is outside on a riverbank and the reception will follow in a fully air-conditioned 100 year old grist mill. The venue is Crooked River Farm which implies its a barn, but its actually fairly fancy instead of a country wedding. The venue reflects this even if the name of the venue doesn't. How can I say "please dress in summer dresses/skirts and appropriate shoes for ladies, and khakis and short sleeved button ups for men" in a non-offensive manner? I realize I can't dictate to people what to wear, but I don't want people to show up and feel uncomfortable because they didn't realize what kind of attire to wear. My venue is brand new (we are the 2nd wedding ever to take place there) so I can't rely on people knowing what its like from past experience either. I am planning on putting the wedding website info on the card as well, but for members of the extended family, I need to have it on the card as well.