In the years after the release of Advanced Warfare, users began typing a singular "F" in chat windows on websites such as Twitch to convey condolences or a sense of sorrow when reacting to any unfortunate news on the Internet, leading streamers and others to refer to this with the phrase "F in the chat".
"F" in Internet slang is often used as a way to pay respects or show sympathy. It originates from the video game "Call of Duty: Advanced Warfare," where players are prompted to press the "F" key on their keyboards to pay respects at a funeral.