The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- OntologyModule (7 members)
- ValueScope (2 members)
- FuelCommodity (0 members)
- HeatTransferUnit (1 member)
- PixelsPerInch (0 members)
- Particle (0 members)
- PartsPerTrillion (0 members)
- WaterFlow (3 members)
- AbatedSteamReformingHydrogen (0 members)
- TimeStamp (0 members)
- ElOntologyModule (0 members)
- Knoteninformation (7 members)
- Mole (0 members)
- DataItem (4 members)
- Apinist (0 members)
- Markup (0 members)
- RoadVehicle (2 members)
- OrganizationalUnit (2 members)
- Normal (0 members)
- SecondaryData (0 members)
- IndustrialProcess (0 members)
- Location (4 members)
- Milli (0 members)
- Week (0 members)
- GridComponent (8 members)
- OSW3daf908ae7905ff2b362477f51f6d66b (4 members)
- OilPowerUnit (0 members)
- Femtogram (0 members)
- LocalFile (0 members)
- HeatExchanger (4 members)
- Megavolt (0 members)
- UnitOfNormality (1 member)
- Biofuel (6 members)
- PoliticalAssumption (0 members)
- RecoveredHeat (0 members)
- EnergyScenario (0 members)
- LengthUnit (18 members)
- MotorGasoline (0 members)
- Pico (0 members)
- TractionMotor (1 member)
- Tax (1 member)
- HeatPlant (3 members)
- GasTurbineVehicle (1 member)
- QuantityValue (7 members)
- Megabyte (0 members)
- MainActivityEnergyProducer (0 members)
- Ammonia (1 member)
- DoseUnit (2 members)
- SteamReformer (0 members)
- ContainerShip (0 members)