UNISYC was an organisation formed in 1994. Its initials (probably) stood for United Nations Security Yard Corps. Its ostensible purpose was to research cutting-edge security technology for defensive purposes.
Around 1996, UNISYC was often involved in squabbles with other United Nations organisations concerning access to alien technology. (PROSE: Interference - Book One, Interference - Book Two) Part of its troop training involved a book called Theoretical Monsters: A Credibility Test which concerned the credibility of various aliens. There was a copy of this book in a UN building in Geneva in 1996. (PROSE: Interference - Book One)