BTWF 

Before They Were Famous

"Did you see that BTWF clip of Angelina? She was so young!"

BTWF by Red22 January 16, 2009

BTWF 

By The Way Fucker, (Usually you would place a comma after the "F Word" and finish what you were saying)

BTWF, I don't like that shirt you are wearing.

BTWF by Kaimily May 29, 2009

Btwfyi 

By the way, for your information... the combination of these two internet abbreviations, normally used to change the subject but also to address the reader directly

Btwfyi guys, i just beat jay at fifa, hes so terrible

Btwfyi by bushboibeats October 20, 2010