Mass Classes
The Galactic Council maintains a classification chart for starships based around their mass. This classification exists separate from the armament classes of armed vessels, though there's a distinction between the Battlehulk mass class and the Carrier mass class in that both describe vehicles that are roughly equivalent in mass ranges, but where Battlehulks must be armed while Carriers can be military vessels or simply enormous cargo ships.
It's also probably worth mentioning that Station Keepers aren't really a mass class for a specific type of ship, it's simply a way of identifying extremely large space stations that are capable of moving between star systems via FTL drives without breaking into multiple pieces.
Vessel mass class is most frequently referenced when referring to military ships, though civilian ships technically fall under these classifications as well, with several de-clawed Battlehulks in service throughout the galaxy as luxury liners or colony ships, though due to the quirk of galactic policy they are now technically carriers.