Navyfield officially uses SS - Submarine, FF - Frigate, DD - Destroyer, CL - Light Cruiser, CA - Heavy Cruiser, BC - Battlecruiser, BB - Battleship, CV - Carrier; with unofficial use of CVE - Escort Carrier, (and P, E, prefixes to the above for event and premium ships). Personally I'm most familiar with BC for battlecruisers nowadays; I imagine the average person would also be comfortable with BattleCruiser abbreviating to BC regardless of how accurate it is...
As a result of years of playing Navyfield, I mark my ship classes in the same way.