There are a few simple constants that we should keep in mind. Two recurring designations attached to the end of the vessel classification, are "G" and "N," standing for vessels capable of launching guided missiles and running on nuclear power, respectively. The only vessels currently in service that wear both of these designations are the Navy's limited crop of modified Ohio-class submarines (which were formerly known as SSBNs, or nuclear-powered ballistic missile submarines).
From there, things get kind of complicated. Carriers wear "CV," for "carrier vessel" and cruisers start with "C," for obvious reasons. Frigates, destroyers and battleships, though, feature "FF," "DD" and "BB," respectively. And each of those can be modified as needed, borrowing a "G," as the navy's frigates, destroyers and cruisers do.
The current system is quite long lived, with the Navy instituting it way back in July 1920. It's obviously evolved since then, but the basic combination of letters and numbers allows easy identification of a vessel's purpose within the fleet. The Naval Vessel Register provides a total breakdown of both the designations in service as well as retired combinations.
Head over and take a look.
If you have any suggestions on a phrase you aren't sure about, be sure to reach out to brandon dot turkus at autoblog dot com, and we'll be sure to feature it in the coming days.