The < key (between left shift, and z on my keyboard, which is swedish qwerty)
does exactly what pressing f2 does.
By default pressing < will take a screenshot(just like f2 does), and changing f2 to toggle fullscreen (instead of f11), it does that too. Strangly it only seems to be able to do either of those 2 things...
Really weird bug I know, and it doesn't ruin the game or anything, but it's just a little annyoing.
Linked issues
Comments
How did I not find that? I did search for it. OK, sorry...
Dupe of MC-68399