The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- BusStation (0 members)
- OceanCurrent (0 members)
- ChangeOfTransverseDimension (0 members)
- DirectEquivalentMethod (0 members)
- Date (0 members)
- UnitPrefix (2 members)
- ProgrammingLanguage (0 members)
- Area (2 members)
- TonPerHectare (0 members)
- DensityUnit (3 members)
- OSW9a49d8d78eed51a4971817c0d4f459b2 (1 member)
- ProcessSustainability (0 members)
- Millimeter (0 members)
- Micromolal (0 members)
- MemoItem (0 members)
- SulphurHexafluoride (0 members)
- CalibrationRange (0 members)
- IndustrialWasteThermalEnergy (0 members)
- NodeSeries (0 members)
- ElectricHeatPump (0 members)
- CrudeOil (2 members)
- WastePowerPlant (0 members)
- ActivityOfARadionuclideUnit (7 members)
- MicrocuriePerMilliliter (0 members)
- Assumption (1 member)
- Resolution (2 members)
- Wood (0 members)
- Terajoule (0 members)
- 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)