After the September 11, 2001, terrorist attacks, staff at the Capitol made simple lapel ribbons to wear immediately in recognition of the significance of the tragedy. The commemoration revived on anniversaries, as in 2003 when this ribbon appeared on lapels. In the 20th century, yellow ribbons, in particular, took on multiple symbolic meanings of fidelity and remembrance. By the late 20th century, the colors used diversified, and causes proliferated. Red ribbons signified recognition of the AIDS crisis in the 1990s, and many other colors and patterns specific to the subject followed, including the U.S. flag pattern used for September 11 memorial ribbons.