Hi
It might have been Shift+F which is "Turn off all screen info"
I'm guessing it toggles between on and off, it doesn't say that and
I have never hit it myself, but I'm pretty sure it would
as the F is very close to the R, which you use to vote for a restart,
that might be a safe bet.
Also if you check your "docs" folder, in the LFS directory, you'll
find the list of keystrokes (in several languages).
Those come in handy sometimes
I hope this helps,
MadFred