For anyone looking for the spine numbers and their order, this will be updated periodically 
Core Books (Hexagon) –
- Traveller Core Rulebook (2016, 2022)
- Central Supply Catalogue (2016, 2022)
- High Guard (2016, 2022)
- Vehicle Handbook
- Traveller Companion
- Field Catalogue
- Specialist Forces
- Robot Handbook
- World Builder’s Handbook
- Bounty Hunter
Charted Space (Triangle) –
- Behind the Claw
- Sword Worlds
- Skandersvik
- Aliens of Charted Space 1
- Aliens of Charted Space 2
- The Glorious Empire
- The Solomani Front
- The Third Imperium
- Aliens of Charted Space 3
- Mercenaries of Charted Space
- Secrets of the Ancients
- The Spinward Extents
- Aliens of Charted Space 4
- Order of Prometheus
- The Trailing Frontier
- Rim Expeditions
- Mysteries of the Ancients
- Wrath of the Ancients
- The Deep and the Dark
Campaigns (Square) –
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