The downward-pointing pink triangle dates to the first concentration camps in Nazi Germany. It was a symbol of persecution and discrimination the Nazis used to mark homosexuals. The homosexual community re-appropriated the pink triangle and now proudly use it as a symbol of identity.
Williams, Cristan. “2008 Houston Transgender Day of Remembrance: Transgenders and Nazi Germany”, [En ligne], https://web.archive.org/web/20080820132817/http://tgdor.org/holocaust.shtml
Shankar, Louis. 2017. How the Pink Triangle Became a Symbol of Queer Resistance, [En ligne], https://hiskind.com/how-the-pink-triangle-became-a-symbol-of-queer-resistance/.