Frog Blast the Vent Core!
There's also a 'CVN', sort of--the "CS Tiger Claw" hats given to people who worked on the Wing Commander movie say "Tiger Claw CVN 2654" on them.
It is a good question. My gut says it's not super carrier, since the Vesuvius is just plain 'CV'... so I lean towards it referencing either that she's a dreadnought in general or specifically that she carries a 'super weapon' (the Phase Transit Cannon).
Hmmm I bet the CVN from the movie was the crew looking up USN listings and saw that most carriers today are CVNs.
I want to also agree it's not super carrier. I would lean more towards the designation meaning a carrier that sports heavy anti-ship weaponry since we have the CV in there. Or it could be a fighter-carrying dreadnaught. But I'd lean towards the former considering CV is used.