The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- SecondaryEnergyCarrierDisposition (0 members)
- DeliveryTimePoint (0 members)
- PixelsPerMillimeter (0 members)
- ElectricalEnergyStorageFunction (0 members)
- EducationalOrganization (1 member)
- BinaryFileFormat (0 members)
- Chain (0 members)
- OeoTerm (0 members)
- GreenhouseGas (4 members)
- Dauer (0 members)
- Biomethane (1 member)
- InternationalTransport (0 members)
- FullLoadHours (0 members)
- EnergyConvertingComponent (9 members)
- LiterPerKilogram (0 members)
- LiquefiedPetroleumGas (0 members)
- User (2 members)
- MarineThermalEnergy (0 members)
- VolumeFraction (0 members)
- DataDescriptor (5 members)
- Faculty (0 members)
- Giga (0 members)
- Hersteller (0 members)
- TopDown (0 members)
- HeatCapacity (0 members)
- Pound (0 members)
- Client (0 members)
- DigitalMaterialIdentifier (0 members)
- CrossSectionDetermination (0 members)
- MarineWaveEnergyTransformation (0 members)
- TankShip (0 members)
- ConventionalEnergyCarrierDisposition (0 members)
- Renewable (0 members)
- PressureUnit (2 members)
- SolarSteamElectricProcess (1 member)
- TextualEntity (1 member)
- Femtomole (0 members)
- SubstitutionMethod (0 members)
- SolarHeatUnit (0 members)
- CombustibleEnergyCarrierDisposition (0 members)
- ColonyFormingUnitPerMilliliter (0 members)
- AmorpheStruktur (0 members)
- TwoAxisTracking (0 members)
- GasTurbineProcess (0 members)
- Population (4 members)
- PassengerTransport (2 members)
- ElectricalEnergyAmountValue (2 members)
- CodeDocumentation (0 members)
- Chemical (0 members)
- TerawattHour (0 members)