The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Transport (3 members)
- NuclearFuel (3 members)
- Co2EmissionValue (0 members)
- Femto (0 members)
- MassVolumePercentage (0 members)
- RotorDiameter (0 members)
- ClosedLoopPumpedHydroStoragePowerPlant (0 members)
- EnergyStorageCapacity (0 members)
- MarineCurrentEnergy (0 members)
- Zepto (0 members)
- OSW8e353a702f1a5e1c8760770961c72185 (1 member)
- NitrogenOxides (2 members)
- CovalentBond (0 members)
- EnergyMarketExchange (1 member)
- CompressedGasEngine (0 members)
- CurationStatusSpecification (0 members)
- SupplySystem (1 member)
- Knotenversion (0 members)
- BleibendeDehnung (0 members)
- Tank (1 member)
- OSW8ebe4c634c0652b2949f75ed62f1267f (1 member)
- TestOntologyClassB11 (0 members)
- Pollution (1 member)
- TemporalRegion (2 members)
- Factsheet (4 members)
- SupplyGrid (3 members)
- HydrogenTurbine (0 members)
- PhysicalMethod (0 members)
- UnitedStatesCustomaryTeaspoon (0 members)
- ChemicalEnergyTransfer (0 members)
- PrüfstückName (0 members)
- MotorisedVehicle (3 members)
- ObereStreckgrenze (0 members)
- AmountPerContainer (2 members)
- OboBasicSubsetOntologyModule (0 members)
- HeatingOil (0 members)
- FrequencyUnit (3 members)
- ContactPerson (0 members)
- ExternalPerson (0 members)
- Zetta (0 members)
- BereitgestellterIdentifikator (2 members)
- PrimaryEnergyCarrierMining (0 members)
- Millisievert (0 members)
- Oberflächenrauheit (0 members)
- ArealPowerDensity (1 member)
- Drachm (0 members)
- EinsteinPerSquareMeterPerSecond (0 members)
- Slope (0 members)
- ElectricalEnergyTransfer (1 member)
- ElectroMotiveGenerator (0 members)