Sometimes also "Core Registration Study". Olga is right about the meaning, but this is how it is called in English (I have just finished translating a protocol for a registration study).

Definition from Lilly's glossary:
Core Registration Studies: Those primary safety and efficacy studies that the relevant government health agency uses to decide whether or not to approve the investigational drug or new use of a marketed drug. These studies are usually phase 3, always well controlled, randomized, of adequate size and, whenever possible, double blind. May also be called Pivotal or Confirmatory Trials.
http://www.lillytrials.com/docs/terminology.html

More references:
http://tinyurl.com/kpeqvq2