A black ribbon is a symbol of remembrance or mourning. Wearing or displaying a black ribbon has been used for POW/MIA remembrance, mourning tragedies, or as a political statement.
Similar to a black armband, the black ribbon is a public display of grief. Individuals or organizations display the ribbon in commemoration of victims after specific incidents. Some examples have included:
TortureProtest.org black ribbon campaign
Melanoma Awareness Ribbon Alternative with White Polka Dots