I got the chance to ask a friend of mine who is into fashion about this topic. She said that there are times that when unless it is specified otherwise for that occasion. A “black tie” event generally permits any length of gowns and dresses. That said, wearing shades of dark and decadent clothing is an excellent match for formal black-tie occasions. A bit of advice, if you are going to buy or invest in a quality dress, make sure that it is a style that will last. Do not waste your money on a dress that will easily fade away when a new fashion style comes in.