The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.

• (DT)Ecology‏‎ (14 members)
• (DT)Energy‏‎ (10 members)
• (DT)Governance‏‎ (2 members)
• (DT)Shipping‏‎ (6 members)
• (NS)Currents‏‎ (1 member)
• (NS)Ecology‏‎ (28 members)
• (NS)Energy‏‎ (14 members)
• (NS)Governance‏‎ (11 members)