Testimony

One's testimony was their complete truth on the matter at hand.

While Dalek Progenitors would normally only activate to a genetically pure Dalek, they possessed a failsafe that would activate them if the Doctor, the Daleks' greatest enemy, gave his testimony that those seeking to activate the device were Daleks. (TV: Victory of the Daleks) When the last three survivors of the New Dalek Empire (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe) were deemed impure by the last Progenitor, they were forced to use the Eleventh Doctor's testimony to activate the device. (TV: Victory of the Daleks)

In the far future, the Testimony Foundation was set up on New Earth to take the testimonies of all of humanity's dead, (TV: Twice Upon a Time) a process that the Twelfth Doctor likened to humanity having built their own version of the Matrix. (PROSE: Twice Upon a Time)