From TARDIS Index File, the free Doctor Who reference.

UNISYC was an organisation formed in 1994, its initials (probably) stood for United Nations Security Yard Corps. Around 1996 it was often involved in squabbles with other UN organisations concerning access to alien technology. (EDA: Interference - Book One) In the late 21st century UNISYC was invited to the East Indes ReVit Zone for the auction of The Relic. (EDA: Alien Bodies) By the 2030s the ISC was a division of UNISYC. (EDA: Alien Bodies)

Training

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. (EDA: Interference - Book One)