The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- AnnotationProperty (55 members)
- Batteries (1 member)
- Category (Class) (6 members)
- Corrosion prevention (1 member)
- Data property (40 members)
- Electrochemistry (1 member)
- Electrodes (1 member)
- Entity (3 members)
- Imported vocabulary (6 members)
- Item (23 members)