Limited Slip?

Just purchased a 99 Wrangler, 4cyl, manual trans. and the seller (original owner), is unsure if the jeep has limited slip. He had not ever taken it off-road. I found a tag today on the housing cover that states "Use limited slip fluid only". Should we assume that it is equiped with this option?
111!!!

i would assume that it does have a limited slip as well. If you jack up both rear tires, turn one tire if it has a limited slip the opposite tire should move in the same direction. If it does not move or moves the opposite direction you probably have an open diff

it would be a factory TracLok, you can take the VIN number into the dealership and for free they will run you a "Build Sheet" which will have on it if you have a LSD as well as other important information.