It implies "Polished but Relaxed."

• Do: Chinos (Navy, Sand, Olive) + a tailored blazer/sports coat + a crisp collared shirt (tucked in) + leather loafers or R.M. Williams boots.
• Don't: Jeans (unless specifically told "Casual"), T-shirts, Polo shirts (unless very high quality and under a jacket), or running shoes.
• Context: For a winery wedding, a linen blazer is perfect. For a city wedding, a wool blazer is safer.