On World Aids Day, the visuals remain. From the pink triangle to the red ribbon, iconic imagery has always been an important aspect in the fight against HIV and AIDS. They served as a common language across borders that helped to unify people.

“It’s a way of making sense of history by visualizing it,” art historian Joan Saab told The Atlantic. Visual design, it turns out, became a weapon in this ongoing war.

Related: [World AIDS Day] Graphic Response from Artists and Ad Agencies Around the World

On World AIDS Day, we are decoding some of the symbols and images that helped activists spread their message and raise awareness. The following stories were compiled by Graphic Intervention, an traveling exhibit curated by Elizabeth Resnick of the Massachusetts College of Art and Design.

Pink Triangle and Silence = Death

The original pink triangle emblem was designed by six gay men calling themselves the “Silence = Death Project” in 1986 and later used by ACT UP (AIDS Coalition To Unleash Power) to produce T-shirts, buttons and stickers as a means of fundraising for the cause.

Historically, the inverted pink triangle is a symbol of oppression. It was used as a marker of homosexual men in Nazi concentration camps much in the same manner that Jewish people were forced to wear the yellow Star of David as an identifier. Wearers of the inverted pink triangle were considered at the bottom of the camp social system and subjected to particularly harsh maltreatment and degradation.

Thus, the appropriation of the symbol of the pink triangle, usually turned upright rather than inverted by Pro-gay activists in the 1970s was a conscious attempt to transform a symbol of humiliation into one of solidarity and resistance. The iconic image has since been borrowed by other artists (see Keith Haring below, for example) and reproduced in variations like the French “Action = Life.”

AIDS Red Ribbon

A loop of red silk ribbon, typically fastened on a lapel or pinned to a shirt, shows the wearer to be sympathetic and supportive of those with HIV/AIDS. Designed by the graphic arts activist group Visual AIDS to increase awareness and promote action to combat AIDS, the red ribbon symbol was introduced in the United States at the 1991 Tony awards ceremony by the group Broadway Cares/Equity Fights AIDS.

In 1993 the US Postal Service released a red ribbon stamp with the caption “”AIDS Awareness.” The AIDS ribbons also provided the impetus for other groups to designate variously colored ribbons for their own causes, such as the pink ribbon worn for breast cancer awareness.

The Death of David Kirby

The photo of AIDS activist David Kirby was taken in his room at the Ohio State University Hospital in May 1990. The photo, taken in both black and white and color by Therese Frare, was included in LIFE magazine in November 1990 and went on to win the 1991 World Press Photo Award.

Tibor Kalman, working with Oliviero Toscani, was preparing a consciousness-raising campaign associated with Benetton products and culture. He saw the Frare photograph in LIFE magazine and suggested that Benetton include it in their advertising campaign. Benetton approached the photographer and Kirby family, gaining consent for the use of the photograph and contributing to an AIDS foundation. When considering whether to stay with black and white or use color the creative team decided that it needed to look like an advertisement, raising the shock value.

Oliviero Toscani went on to create equally shocking images for the Benetton campaign incorporating sexual taboos and discrimination.

Keith Haring’s Ignorance = Fear/Silence = Death

The goal of this poster was to bring attention to the prejudice surrounding the growing AIDS crisis in the late 1980s. “Silence = Death” — a painting by Keith Haring — depicts three figures in positions that suggest a modern day embodiment of the three wise monkeys who “see no evil, hear no evil, speak no evil”. Here the purpose is to campaign on behalf of the American people to overcome the prejudice that prevents protecting their health and the health of their loved ones.

Haring, a social activist and a gay man who was actively involved with ACT UP, continued to use his iconic art as a way of raise public awareness up until he died of AIDS complications in 1990. The Haring angel altarpiece above is on up on permanent display in Grace Cathedral in San Francisco.