A vessel capable of faster than light interstellar travel using the Hyperspace Drive.

In the case of military ship designation letters, interstellar capability is designated using the letter 'I'.

Hence an interplanetary Carrier is designated CV and an Interstellar-capable Carrier is designated CVI

Civilian Ship Classes

Class 1000 C1
Class 2000 C2
Class 3000 C3
Class 4000 C4
Class 5000 C5
Liner C5L
Packet Ship C3P
Armed Merchant AMI AMI
Q Ship CQ

Military Ship Classes

Carrier CVI
Battleship BBI
Plasmatic Battleship PBI
Automatic Battleship ABI
Missile Battleship MBI
Heavy Cruiser CAI
Missile Heavy Cruiser CMI
Assault Landing Ship ALSI
Marine Assault Ship MAI
Light Cruiser CLI
Light Carrier DVI
Destroyer DDI
Transport Ship TPTI
Assault Carrier AVI
Escort Carrier EVI
Support Carrier SVI
Swarm Multiple Pacifier Ship MPSI