Sanctioned

As part of the tithes every world owes the Imperium, each must collect all who show any sign of psychic abilities for the Black Ships to carry to Terra. There, the Adeptus Astra Telepathica conduct fearsome testing known as sanctioning for power levels, mental strength, and other factors that decide each Psyker’s fate. To survive is to have passed these tests, and gone on to serve the Emperor as a Sanctioned Psyker.
If a Sanctioned character gains the Psyker elite advance, he does not gain the Corruption normally inflicted with that advance and starts at psy rating of 2 instead of 1