Planetary classification systems in Duyi'zu are different than one in other universes and were used by the Federation to categorize planets in this universe. Various factors were taken into consideration, including atmospheric composition, surface temperature, vegetation and size. The classification system used by the Federation used single-letter designations, for example class M to describe a planet able to support humanoid life for long periods, while the Vulcans used the term "Minshara class" to describe a similar planet.
Planetary classes[]
| Class | Description | Examples |
| Class D | Planetoid or moon; little to no atmosphere. Uninhabitable. | Regula, Weytahn |
| Class H | Generally uninhabitable. | Tau Cygna V |
| Class J | Gas giant | Jupiter, Saturn |
| Class K | Adaptable with pressure domes | Mudd, Theta VIII, Mars (class K transjovian) |
| Class L | Marginally habitable. No animal life. Only vegetation life. | Indri VIII |
| Class M | Terrestrial | Earth, Vulcan, Cardassia Prime, Risa, Bajor |
| Class N | Sulfuric | Venus |
| Class T | Gas giant | |
| Class Y | "Demon" | Silver Blood planet |