Trucker talk used on CB radios to make the number 9 sound cool when relaying directions, coordinates or instructions. Also used in the military. You have to be an uptight angry white male with either a buzz cut, aviator sunglasses or a flannel shirt to use this term.
"We've located Charlie at DELTA, BRAVO, point NINER, over."
"The $2.99 omlette and vanilla shake deal is at the Oasis off of I-two-oh-niner, little buddy. For another 2 bucks the waitress with show you her tankers."