The Ballroom Bustle is often called an Overbustle. I've started calling this a Ballroom Bustle because it results in making the gown look like a typical ballroom gown. Buttons or hooks are positioned at the waist and loops are sewn at carefully plotted points on the train so that when they are looped on the buttons the train is all one length. It's not always possible to have every bit of the train to be perfectly straight, but a skilled sewist can come very close.