An inverted black triangle is a lesbian or feminist symbol of pride and solidarity. It originates from Nazi Germany, where it was used in concentration camps to designate women considered 'anti-social' (ie. a threat to Nazi family values) such as lesbians and prostitutes. As a symbol of lesbian pride it is considered the female counterpart to the pink triangle, which was a symbol for gay men.
See also homosexuals in Nazi Germany, rainbow flag.
External link
- A short explanation of the origin of pink and other queer triangles (http://www.enqueue.com/ria/triangles.html)