A way to show the utmost form of respect during an unfortunate or tragic event. This form of flattery stems from the world of gamers. "Press F to pay respects" is the caption in a scene that occurs at a funeral in Call of Duty: Advanced Warfare. See oof for a less formal method of condolences.

Often used to show respect on the Internet.

It is often used to pay respect online.

Press F to Pay Respects is an action prompt from a quick time event featured in the first-person shooter Call of Duty: Advanced Warfare. Following the game’s release in November 2014, many players mocked the event online for forcing interactivity into the cut scene.

F is what is used to show respects after a serious event/tragedy.

is

A test grade which will shortly be followed by the bullshit of your parents.