I also happen to like the conceit:
NAVAL TERMINOLOGY:
- ACS = Auxiliary Class (Up to 2,500 tons) - Minor & Escort Combatants/Tertiaries
- BCS = Battle Class (~3,000 to 100,000 tons) - Subcapital Ships/Secondaries
- CCS = Capital Class (100,000 - 250,000 tons: A subcategory of Fleet Class) - Capital Ships/Primaries
- FCS = Fleet Class (~100,000 / 250,000 - 1,000,000 tons) - Large Capital Ships/Primaries
CIVILIAN / COMMERCIAL (& COLLOQUIAL) TERMINOLOGY:
- ACS = "Adventure" Class - Smaller Commercial Vessels / Colloquial Jargon
- BCS = Bulk Class - Large Corporate Commercial Vessels