Yea, I had heard that. They thought that NCC sounded better than NC.
Keep in mind...current real world designations, at least for the United States go as follows:
USS: United States Ship
CURRENT US NAVY SHIP CLASSIFICATIONS
Designations currently in use or officially in effect are listed here, all others are no longer in use. The letter "N" when used as the last letter of a ship classification symbol denotes nuclear propulsion.
If you do not find the classification symbol you are looking for here it may be in the US Navy Inactive Classification Symbol file.
COMBATANT SHIP CATEGORY
Warship classification
   Aircraft Carrier Type
      All ships designed primarily for the purpose of conducting combat
      operations by aircraft which engage in attacks against airborne,
      surface, sub-surface and shore targets.
         Conventional Take Off and Landing (CTOL) Aircraft Carriers
            Multi-purpose Aircraft Carrier                CV
            Multi-purpose Aircraft Carrier                CVN
            (Nuclear-Propulsion)
   Surface Combatant Type
      Large, heavily armed, surface ships which are designed primarily to
      engage enemy forces on the high seas.
         Battleships
            Battleship                                    BB
         Cruisers
            Gun Cruiser                                   CA
            Guided Missile Cruiser                        CG
            Guided Missile Cruiser                        CGN
            (Nuclear-Propulsion)
         Destroyers   
            Destroyers                                    DD
            Guided Missile Destroyer                      DDG
         Frigates
            Frigate                                       FF
            Guided Missile Frigate                        FFG
            Radar Picket Frigate                          FFR
            Frigate (Reserve Training)                    FFT
   Submarine Type
      All self-propelled submersible types regardless of whether
      employed as combatant, auxiliary, or research and development
      vehicles which have at least a residual combat capability.
         Attack Submarines
            Submarine                                     SS
            Submarine                                     SSN
            (Nuclear-Powered)
         Ballistic Missile Submarines
            Ballistic Missile Submarine                   SSBN
            (Nuclear-Powered)
   Other Combatant Classification
      Patrol Combatant Type
         Combatants whose mission may extend beyond coastal duties and
         whose characteristics include adequate endurance and sea
         keeping providing a capability for operations exceeding 48 hours
         on the high seas without support.
            Patrol Ships
               Patrol Combatant                           PG
      Amphibious Warfare Type Ships
         All ships having organic capability for amphibious assault and
         which have characteristics enabling long duration operations on the
         high seas.
            Amphibious Helicopter/Landing Craft Carriers
               Amphibious Assault Ship (General Purpose)  LHA
               Amphibious Assault Ship (Multi-Purpose)    LHD
               Amphibious Transport Dock                  LPD
               Amphibious Assault Ship (Helicopter)       LPH
            Landing Craft Carriers
               Amphibious Cargo Ship                      LKA
               Dock Landing Ship                          LSD
               Medium Landing Ship                        LSM
               Tank Landing Ship                          LST
            Miscellaneous
               Amphibious Command Ship                    LCC
   Combat Logistics Type Ships
      Ships which have the capability to provide underway replenishment
      to fleet units.
         Underway Replenishment
            Ammunition Ship                               AE
            Combat Store Ship                             AFS
            Oiler                                         AO
            Fast Combat Support Ship                      AOE
            Replenishment Oiler                           AOR
   Mine Warfare Type Ships
      All ships whose primary function is mine warfare on the high seas.
         Minesweepers
            Minesweeper - Ocean                           MSO
         Mine Countermeasures Ships
            Mine Countermeasures Ship                     MCM
            Mine Countermeasures Support Ship             MCS
            Minehunter, Coastal                           MHC
   Coastal Defense Ships
      All ships whose primary function is coastal patrol and interdiction.
         Special Warfare
            Patrol, Coastal                               PC
   Auxiliary classification
      Mobile Logistics Type Ships
         Ships which have the capability to provide direct material support to
         other deployed units operating far from home base.
            Material Support
               Destroyer Tender                           AD
               Repair Ship                                AR
               Submarine Tender                           AS
      Support Type Ships
         A grouping of ships designed to operate in the open ocean in a
         variety of sea states to provide general support to either combatant 
         forces or shore based establishments. (Includes smaller auxiliaries
         which by the nature of their duties, leave inshore waters).
            Fleet Support
               Salvage Ship                               ARS
               Submarine Rescue Ship                      ASR
               Auxiliary Ocean Tug                        ATA
               Fleet Ocean Tug                            ATF
               Salvage and Rescue Ship                    ATS
            Other Auxiliaries
               Auxiliary Crane Ship                       ACS
               Auxiliary General                          AG
               Deep Submergence Support Ship              AGDS
               Environmental Research Ship                AGER
               Miscellaneous Command Ship                 AGF
               Missile Range Instrumentation Ship         AGM
               Oceanographic Research Ship                AGOR
               Ocean Surveillance Ship                    AGOS
               Surveying Ship                             AGS
               Auxiliary Research Submarine               AGSS
               Hospital Ship                              AH
               Cargo Ship                                 AK
               Vehicle Cargo Ship                         AKR
               Gasoline Tanker                            AOG
               Transport Oiler                            AOT
               Transport                                  AP
               High Speed Transport                       APD
               Cable Repair Ship                          ARC
               Aviation Logistics Support Ship            AVB
               Auxiliary Aircraft Landing Training Ship   AVT
US NAVY SERVICE CRAFT CLASSIFICATIONS
Designations currently in use or officially in effect are listed here, all others are no longer in use. The letter "N" when used as the last letter of a service craft classification symbol indicates a non-self-propelled (n-s-p) version of a similar self-propelled (s-p) service craft.
If you do not find the classification symbol you are looking for here it may be in the US Navy Inactive Classification Symbol file.
SUPPORT CRAFT CATEGORY
Support Craft Classification
   Service Type Craft
      A grouping of navy-subordinated craft (including non-self-propelled)
      designed to provide general support to either combatant forces or 
      shore-based establishments.
         Dry Docks (Non-self-propelled)
            Large Auxiliary Floating Dry Dock             AFDB
            Small Auxiliary Floating Dry Dock             AFDL
            Medium Auxiliary Floating Dry Dock            AFDM
            Auxiliary Repair Dry Dock                     ARD
            Medium Auxiliary Repair Dry Dock              ARDM
            Yard Floating Dry Dock                        YFD
         Tugs (Self-propelled)
            Large Harbor Tug                              YTB
            Small Harbor Tug                              YTL
            Medium Harbor Tug                             YTM
         Tankers (Self-propelled)
            Fuel Oil Barge                                YO
            Gasoline Barge                                YOG
            Water Barge                                   YW
         Lighters and Barges
            Self-propelled
               Covered Lighter                            YF
               Refrigerated Cover Lighter                 YFR
               Harbor Utility Craft                       YFU
               Garbage Lighter                            YG
            Non-self-propelled
               Open Lighter                               YC
               Car Float                                  YCF
               Aircraft Transportation Lighter            YCV
               Covered Lighter                            YFN
               Large Covered Lighter                      YFNB
               Lighter (Special purpose)                  YFNX
               Refrigerated Covered Lighter               YFRN
               Range Tender                               YFRT
               Garbage Lighter                            YGN
               Gasoline Barge                             YOGN
               Fuel Oil Barge                             YON
               Oil Storage Barge                          YOS
               Sludge Removal Barge                       YSR
               Water Barge                                YWN
         Other Craft
            Self-propelled
               Deep Submergence Rescue Vehicle            DSRV
               Deep Submergence Vehicle                   DSV
               Submersible Research Vehicle               NR
               Ferry Boat or Launch                       YFB
               Dredge                                     YM
               Patrol Craft, Training                     YP
               Seaplane Wrecking Derrick                  YSD
               Torpedo Trials Craft                       YTT
            Non-self-propelled
               Barracks Craft                             APL
               Floating Crane                             YD
               Diving Tender                              YDT
               Dry Dock Companion Craft                   YFND
               Floating Power Barge                       YFP
               Salvage Lift Craft                         YLC
               Dredge                                     YMN
               Gate Craft                                 YNG
               Floating Pile Driver                       YPD
               Floating Workshop                          YR
               Repair and Berthing Barge                  YRB
               Repair, Berthing and Messing Barge         YRBM
               Floating Dry Dock Workshop (Hull)          YRDH
               Floating Dry Dock Workshop (Machine)       YRDM
               Radiological Repair Barge                  YRR
               Salvage Craft Tender                       YRST
         Unclassified Miscellaneous
               Unclassified Miscellaneous Unit            IX
               Submersible Craft                          X
         USS Constitution
      
         Note:   The USS Constitution formerly IX 21 was reclassified 
                 to none, effective September 1, 1975 as per
                 SECNAVNOTE 5030 dated September 2, 1975.
So you can see the direction I intended to go in...all Starfleet ships have either NCC or NX, but I wanted, since they are military, to instead have military designations, IE class listed before the registration number.
I could, of course, leave the USS and NCC for Starfleet alone so people will find it less disruptive, and just concentrate on military designations.
The codes I chose are similar to the old SFB codes for ships.