Leet computer speak for telling someone to shut the fuck up.
Jim: "My CPU is 10x the processing power of your CPU, furthermore, I can run 52 appli--"
Joe: "SHUT TEH FACE!"
a fun way of telling others to shut the fuck up because they sound like a bonifide retard
you shut teh face, only open teh face to eat teh toasty oats
recommending someone to shut up before an object of round quality is shoved in the mouth
shut teh face, only allowed open when eating teh toasty oats
Commonly pronounced SHUT TEH FACE, as spelled, STF should always be capitalized when used online. It is the most 1338 way of saying shut the fuck up cause your way n00ber than yours truly.
erik-otaku : Whatever toast, come to the next party and ill own you.
min.dan: SHUT TEH FACE.