 When morning dress became common (in the modern sense, using a morning tailcoat rather than a frock coat), it was considered less formal than a frock coat, and even when the frock coat was increasingly phased out, morning dress never achieved full dress status.Therefore, in the 21st century, "full dress" often refers to white tie only.Today's semi-formal black tie (originally "dinner clothes") was initially described as informal wear, while the "lounge suit," now standard business wear, was originally considered (as its name suggests) casual wear.