Planetary Classifications

Memory Alpha Planetary Classification System
 Class     Description     Examples
 Class D     Planetoid or moon; uninhabitable     Paan Mokar, Regula
 Class H     Generally uninhabitable     Tau Cygna V
 Class J     Gas giant     Jupiter, Saturn
 Class K     Adaptable with pressure domes     Mudd, Theta 116 VIII
 Class L     Marginally habitable     Indri VIII
 Class M     Terrestrial     Earth, Risa, Bajor
 Class N     Sulfuric     Venus
 Class T     Gas giant
 Class Y     "Demon"     Silver Blood planet