Level 5 planet

A Level 5 planet was a designation used by Galactic Law in reference to certain worlds, with the implication that it referred to relatively primitive planets not yet fully integrated into galactic civilization. Seeding on a Level 5 planet is prohibited by Galactic Law. (TV: Partners in Crime)

Known Level 5 Planets

 * Earth, as of 1979 and 2008. (TV: City of Death, Voyage of the Damned, Partners in Crime, The Eleventh Hour, Revenge of the Slitheen)