The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- AopoA (0 members)
- Aopoa (5 members)
- Apache License (5 members)
- Apartment Habs (4 members)
- Apocalypse Arms (15 members)
- Apocalypse Arms images (1 member)
- Apollo Images (2 members)
- Apollo Medivac images (16 members)
- Apollo Triage images (16 members)
- Apollo series (2 members)
- Aponte Explorer images (1 member)
- Appliance manufacturers (1 member)
- Appointment Missions (4 members)
- April Fool's (5 members)
- Ar (0 members)
- Ar-2 (0 members)
- ArcCorp (21 members)
- ArcCorp (planet) (1 member)
- ArcCorp AO Missions (13 members)
- ArcCorp images (29 members)
- Archangel Station images (1 member)
- Architecture images (22 members)
- Archon Base images (21 members)
- Arclight images (20 members)
- Arden-CL Backpack images (3 members)
- Arden-SL Helmet images (1 member)
- Arden-SL images (5 members)
- Arden-SL set (5 members)
- Area18 (3 members)
- Area18 images (110 members)
- Area 18 (3 members)
- Areas (1 member)
- Aremis (1 member)
- Aremis Post (0 members)
- Aremis images (4 members)
- Ares Inferno Images (2 members)
- Ares Inferno images (84 members)
- Ares Ion images (35 members)
- Ares inferno images (1 member)
- Ares series (2 members)
- Argo Astronautics (7 members)
- Argo Series (0 members)
- Argus Helmet images (1 member)
- Arial (2 members)
- Arial images (19 members)
- Aril Helmet images (1 member)
- Aril images (10 members)
- Aril set (5 members)
- ArmaMod (21 members)
- Armitage (planet) (1 member)
- Armor Shops (1 member)
- Armor images (10 members)
- Armor set (40 members)
- Armor set images (3 members)
- Arms armor (29 members)
- Arms armor images (18 members)
- Around The Verse (15 members)
- Around the Verse (15 members)
- Arrastra images (0 members)
- Arrow I images (1 member)
- Arrow images (64 members)
- Arrow series (0 members)
- Arrowhead Sniper Rifle images (24 members)
- Art (1 member)
- Article management templates (6 members)
- Article stubs (1,303 members)
- Articles with hatnote templates targeting a nonexistent page (66 members)
- Artificial Intelligence Characters (1 member)
- Artificial Planet (2 members)
- Artimex Helmet images (1 member)
- Artimex images (7 members)
- Artimex set (4 members)
- Artwork images (1 member)
- Ascension Astro (9 members)
- Ashana (1 member)
- Aspire Grand images (2 members)
- Assault rifles (6 members)
- Associated Sciences and Development (3 members)
- Asteroid Belt (51 members)
- Asteroid Cluster (12 members)
- Asteroid Formations (75 members)
- Astronomical Objects (686 members)
- Astronomy (2 members)
- Asura (1 member)
- Atlas-Class Cargo Ferry images (3 members)
- Atlas series (2 members)
- Attachment (1 member)
- Attrition Repeater images (2 members)
- Atzkav Electron Sniper Rifle images (7 members)
- Atzkav Sniper Rifle (1 member)
- Atzkav Sniper Rifle images (13 members)
- Audio templates (1 member)
- Aurora CL images (19 members)
- Aurora ES images (22 members)
- Aurora LN images (24 members)
- Aurora LX images (25 members)
- Aurora MR images (58 members)
- Aurora series (16 members)
- AutoWikiBrowser (0 members)
- AutoWikiBrowser images (2 members)