A short video showing a student's graduation mortarboard decorated with a QR code has gone viral for the message it links to: A list of school shooting victims and a call to action.

The video has been viewed more than 3 million times. It shows the decorated cap being scanned on an iPhone. The code directs the phone to a page titled "I graduated. These high school students couldn’t."

The page contains a simple image with white text on a black background. It lists dozens of school shooting victims, including the name Kendrick Castillo, who was killed in a school shooting in Colorado last week.

At the bottom, the image urges action: "protect our students. vote." It lists the names of two gun reform activism websites.

The video and unique cap design was created by Gina Warren, an 18-year-old senior at Teays Valley High School in Ohio, The Washington Post reports. Warren hoped to draw attention to gun violence with her unique cap, she said.

"I wanted to send a message to everybody who saw it that no matter where you stand politically ... it all boils down to the fact that these kids won't be able to attend class or attend prom or attend graduation," she told the newspaper.

The list is intended to include school shooting victims going back to 1999's Columbine shooting, she said.

Warren has received widespread support on social media for her message. In response to numerous social media users asking for the code for use on their graduation caps, she has provided the code for others to use: