The paper defines and studies
links between the prime ideals of a noncommutative fully bounded noetherian ring,
and their role as obstructions to localizability: a localization with properties similar
to those of the localization of a commutative ring at a prime ideal, can be
constructed if and only if the equivalence class determined by the links is finite.
For rings with polynomial identity, the links are described in more detail
via an inductive procedure over the PI-degree, and several examples are
constructed.