The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Material (3 members)
- mathematics (0 members)
- taxonomic bridge ontology module (0 members)
- industry sector (0 members)
- gasworks gas (0 members)
- cost (7 members)
- chemical substance (0 members)
- nuclear binding energy (0 members)
- latent solid-fluid heat storage object (0 members)
- My OWL Test Class (0 members)
- sectoral emission (0 members)
- rood (0 members)
- water turbine (0 members)
- sub bituminous coal (0 members)
- Material Structure (3 members)
- non-metallic mineral (0 members)
- Environmental Temperature (0 members)
- solid renewable fuel (0 members)
- gasoline car (0 members)
- citation (0 members)
- physic (0 members)
- electric traction motor (0 members)
- freight train station (0 members)
- publisher role (0 members)
- software licence (0 members)
- theoretical computer science (0 members)
- template generated ontology module (0 members)
- compressed biomethane (0 members)
- liquefied petroleum gas car (0 members)
- diesel engine (0 members)
- author identification (0 members)
- slug (0 members)
- hard coal power unit (0 members)
- Elliptical (0 members)
- Blank (0 members)
- absorbance unit (0 members)
- fossil combustion fuel (6 members)
- Category that does not allow to add additional properites (0 members)
- Aging Interval (0 members)
- combined heat and power generation process (0 members)
- collaboration (7 members)
- switchyard (0 members)
- family name (0 members)
- transport performance value (0 members)
- grid supplied electric vehicle (0 members)
- fiat object part (1 member)
- academic organization role (0 members)
- project proposal (0 members)
- fee (0 members)
- kibibyte (0 members)