Romana II noted that, in terms of applied socioenergetics, a planet in E-Space was losing its grip on level-two development and that a society that evolved backwards must be subject to powerful forces restraining it. (TV: State of Decay)
Comparable labels were applied to other level 2 planets (PROSE: Ghosts of India), level 4 (AUDIO; The Four Doctors), level 5 planets (TV: City of Death onwards) and level 6 planets (PROSE: Ghosts of India), other than grade 3 planets (TV: The Ribos Operation) and class 3 type planets. (PROSE: The Pit)