Rest in power
An American trans girl named Leelah Alcorn killed herself in 2014 because she could not deal with her parents' transphobia. Even after she died, her parents still didn't treat her right and they called her by her deadname (name used before transitioning) instead of the name she wanted to be called. People used "rest in power" to honor Ms. Alcorn and recognize the fact that she wasn't treated right as a transgender person, even after she died.