While the rainbow flag has become the most popular and easily recognizable symbol of the LGBT community, the inverted pink triangle is easily one of the oldest.
Very popular and widely recognised, the pink triangle is rooted in World War II times, and reminds us of the tragedies of that era. Although gay people were only one of the many groups targeted for extermination by the Nazi regime, it is unfortunately the group that history often excludes. Each prisoner in the concentration camps wore a coloured inverted triangle to designate their reason for incarceration, and hence the designation also served to form a sort of social hierarchy among the prisoners.
A green triangle marked its wearer as a regular criminal; a red triangle denoted a political prisoner. Two yellow triangles overlapping to form a Star of David designated a Jewish prisoner. The pink triangle was for homosexuals. In the 1970s, gay liberation groups resurrected the pink triangle as a popular symbol for the gay rights movement. Not only is the symbol easily recognized, but it draws attention to oppression and persecution, then and now.
For more information about other symbols of the LGBTI community, click here:
https://algbtical.org/2A%20SYMBOLS.htm