UAF stands for Unamerican Activities Force. They were usually Federal agents who worked to ferret out Communist sympathizers in the American population. UAF armor was advanced light armor with a small stealth bonus (the step up from it was Chinese Hei Gui/"Black Ghost" armor). Its complement was UAF helmet.
The name is based on the real-life "House Unamerican Activities Committee" (HUAC) in the US Congress in the 1950s, created to investigate Communists in government and media.
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