This supplement contains a compilation of major facts about the society, culture and history of the Traveller Imperium and its neighbours. With its companion booklet, Library Data (A-M), this booklet completes the basic encyclopaedia of the Traveller Universe.

Included are data entries N through Z, plus essays dealing with the Mapping of Imperial Space, the Imperial Nobility, the history of the Spinward Marches, and the political situation on the Solomani Rim.