An acronym standing for "Tips for Life" and is usually followed by a suggestion to prevent someone from looking like a n00b.
If someone were to fart and exclaim, "Guys I farted!"
You may say, "TFL: Don't announce to us that you farted."
-or-
TFL: don't sound like an idiot.
You may say, "TFL: Don't announce to us that you farted."
-or-
TFL: don't sound like an idiot.
by Nick Wedge and Ryan Wilson May 10, 2005