The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- UnitOfMeasure (1 member)
- Ship (2 members)
- Megajoule (0 members)
- EnergyStorageFunction (5 members)
- ProgramParameter (0 members)
- MoleFraction (0 members)
- EnergyBalanceSectorDivision (0 members)
- Tunnel (0 members)
- ElectricityImport (0 members)
- Fluid (10 members)
- Contract (0 members)
- QuantityValue (22 members)
- FurnaceCharacteristic (4 members)
- TubeCollector (0 members)
- ChemicalEnergyStorageFunction (0 members)
- Grips (0 members)
- SulphurDioxide (0 members)
- Acre (0 members)
- EmissionPrice (2 members)
- MomentumUnit (1 member)
- NegativeEmission (0 members)
- ParticleRadius (0 members)
- MySpecialEventType (1 member)
- GasFiredPowerUnit (0 members)
- DieselCar (0 members)
- MegawattHour (0 members)
- RedoxReaction (2 members)
- Foundation (0 members)
- HalfLife (0 members)
- MilligramPerSquareMeter (0 members)
- AgingTemperature (0 members)
- MagneticFluxDensityUnit (1 member)
- Economy (0 members)
- PassengerTrainStation (0 members)
- MetaDeviceCategory (0 members)
- ElectrochemicalReaction (0 members)
- AreaValue (0 members)
- PrimaryModellingPurpose (0 members)
- GewichteteYKoordinate (0 members)
- Remuneration (0 members)
- Steel (0 members)
- Adsorption (0 members)
- MarketPremium (1 member)
- Coal (3 members)
- EnergyAmountValue (3 members)
- MaterialDesignation (0 members)
- Association (0 members)
- EnergyStorageObject (9 members)
- MainReleaseOntologyModule (0 members)
- User (1 member)