Black tie parties mean formal. Formal wedding, charity galas and award ceremonies will most likely call for this dress code. A tea-or–floor length gown is the way to go. s of parties that will most likely call for this dress code. Be sure not to be spilling over your necklines or showing too much leg with a racy slit. Accessorizing with a dramatic necklace or dangling earrings works perfectly – but only choose one or the other.