Nomenclature History

Warships in the United States Navy were first designated and numbered in a system originating in 1895. Under this system, ships were designated as "Battleship X", "Cruiser X", "Destroyer X", "Torpedo Boat X" and so forth where X was the series hull number as authorized by the US Congress. These designations were usually abbreviated as "B-X", "C-X", "D-X", "TB-X," etc. This system became cumbersome by 1920, as many new ship types had been developed during World War I that needed new categories assigned, especially in the Auxiliary ship area.

To rectify this problem, on 17 July 1920, Acting Secretary of the Navy Robert E. Coontz issued General Order No. 521, "Standard Nomenclature for Naval Vessels." This document created a standardized system of alpha-numeric symbols to identify ship types such that all ships were now designated with a two letter code and a hull number, with the first letter being the ship type and the second letter being the sub-type. For example, the destroyer tender USS Melville, first commissioned as "Destroyer Tender No. 2" in 1915, was now re-designated as "AD-2" with the "A" standing for Auxiliary, the "D" for Destroyer (Tender) and the "2" meaning the second ship in that series. Ship types that did not have a sub-classification simply repeated the first letter. This meant that Battleships became "BB-X" and Destroyers became "DD-X" with X being the same number as previously assigned. Ships that changed classifications were given new hull numbers within their new designation series.

The Navy has updated these designations many times over the past century with the most recent (as of 2019) being "Classification of Naval Ships and Craft, SECNAVINST 5030.8C" which was issued in 2016. See below for copies of both the 1920 and the 2016 documents.

The designation "USS" standing for "United States Ship" was adopted in 1909. Prior to that time, no designation was used in official documents. New-construction ships not yet in commission do not use "USS" and are instead prefixed with "PCU" which stands for "Pre-Commissioning Unit." Ships that are out of commission also do not use "USS" and are properly referenced only by their names.

It should be noted that in the United States Navy, unlike European Navies, the first ship in a class to be authorized by the US Congress is the designated class leader (class name ship), regardless of the order in which the ships of that class are laid down, launched or commissioned. For example, contrary to many European texts, for the last class of "Standard" battleships, the battleship USS Colorado BB-45 (commissioned 30 August 1923) is the class leader under USN designation standards, not USS Maryland BB-46 (commissioned 21 July 1921). These battleships are thus properly designated as being "USS Colorado BB-45 Class" and not as "USS Maryland BB-46 Class."

Please note that the listings below include many designations that are no longer in use by the current-day US Navy and that others were proposed designations not actually used or were intended for ships that were never built. Red italicized designations are for those ships actually in commission or currently under construction as of the present time (2019).

Aircraft Carriers

ACVAircraft Carrier, Auxiliary
AVGEscort Carrier, Auxiliary
AVTAircraft Carrier, Training Ship
CVAircraft Carrier
CVAAircraft Carrier, Attack
CVANAircraft Carrier, Attack, Nuclear Powered
CVBAircraft Carrier, Large
CVEAircraft Carrier, Escort
CVGHAircraft Carrier, Guided Missile Helicopter
CVHAircraft Carrier, Helicopter
CVHAAircraft Carrier, Helicopter Assault
CVHEAircraft Carrier, Escort, Helicopter
CVLAircraft Carrier, Light
CVNAircraft Carrier, Nuclear Powered
CVSPrior to 1957: Seaplane Carrier
CVSAfter 1957: Anti-Submarine/Support Carrier
CVTAircraft Carrier, Training Ship
CVUAircraft Carrier, Utility
CVVAircraft Carrier, Vertical Take Off And Landing

The ex-collier USS Langley AC-3 was rebuilt and recommissioned as the first US aircraft carrier CV-1 on 20 March 1922. The CVB designation was approved by the Secretary of the Navy on 10 June 1943 and the CVL designation was approved on 15 July 1943. The CVS designation was established in 1953 with USS Bunker Hill (CVS-17) being the first so designated on 8 August 1953, although she was in reserve at the time and never did recommission. The designation CVA replaced both CV and CVB on 1 October 1952. CVL went out of use on 15 May 1959 when the last light carrier was decommissioned. With the decommissioning of the last CVS in 1974, CV and CVN replaced CVA and CVAN on 30 June 1975 as carriers were now considered to be multi-mission capable rather than specialized. The CV (non-nuclear) designation went out of service when the last conventionally powered carrier, USS Kitty Hawk CV-63, was decommissioned on 12 May 2009.

Escort Aircraft Carriers were originally designated AVG (Escort Carrier, Auxiliary) on 31 March 1941, with the USS Long Island AVG-1 being the first ship so commissioned on 2 June 1941. This designation was changed on 20 August 1942 to ACV (Aircraft Carrier, Auxiliary), and then changed again on 15 July 1943 to CVE. Escort Carriers built for the British Royal Navy were designated BAVG until they were transferred. The CVE designation went out of use when the remaining escort carriers were reclassified AKV (Auxiliary, Aircraft Ferry) on 7 May 1959.

A common question is "what does the 'V' stand for in CV or CVA or CVS or CVE?"

[Thanks to C. Bossie who provided much of the following answer.]

The following is taken from "United States Naval Aviation 1910-1995, Appendix 16: US Navy and Marine Corps Squadron Designations and Abbreviations":

On 17 July 1920, the Secretary of the Navy prescribed a standard nomenclature for types and classes of NAVAL VESSELs, including aircraft, in which lighter-than air craft were identified by the type "Z" and heavier-than air craft by the letter "V". The reference also speculates that: "The use of the "V" designation has been a question since the 1920s. However, no conclusive evidence has been found to identify why the letter "V" was chosen. It is generally believed the "V" was in reference to the French word volplane. As a verb, the word means to glide or soar. As a noun, it described an aeronautical device sustained in the air by lifting devices (wings), as opposed to the bag of gas that the airships (denoted by "Z") used. The same case may be regarding the use of "Z". It is generally believed the "Z" was used in deference to Count Ferdinand von Zeppelin. However, documentation has not been located to verify this assumption."

In European NATO Countries, "R" is used to designate an aircraft carrier.


BBattleship (prior to 1920)
BBBattleship (after 1920)
BBCBattleship, Command Ship
BBGBattleship, Missile
BBHBattleship, Helicopter
MMonitor (prior to 1920)
BMMonitor (after 1920)

The early pre-dreadnoughts Maine and Texas were commissioned as "Second Class Battleships" but apparently did not receive hull series numbers. Maine was originally designated as Armored Cruiser #1 (ACR-1) but was reclassified during construction.

Many pre-dreadnoughts were colloquially known as "Coastal Defense Ships" as they were not designed nor intended to fight far from home. Some of these were officially renamed as "Coast Battleship #X" (with "X" being their hull number) in March - April 1919 in order to free up their names for new construction. Surviving pre-dreadnoughts were reclassified as "Battleships" and given the BB designation in the 17 July 1920 assignment, although many of these were then rapidly scrapped under the terms of the Washington Naval Limitation Treaty.

The "BBC" "BBG" and "BBH" designations were all for proposed conversions of Iowa class (BB-61) battleships. The first two were developed during the 1950s while the last one was planned during the 1980s commissions. None of these conversions ever took place.

Monitors were coastal defense ships of the 1890s, obsolete even as commissioned.


ACRArmored Cruiser (prior to 1920)
CCruiser (prior to 1920)
CACruiser, First Line (1920 to 1921)
CAArmored Cruiser (1921 to 1931)
CAHeavy Cruiser (after 1931)
CAGGuided Missile Heavy Cruiser - Heavy cruiser converted to carry missiles
CBLarge Cruiser
CBCLarge Command Ship
CCBattlecruiser (prior to 1961)
CCCommand Cruiser or Command Ship (after 1961)
CFFlight-deck Cruiser
CGGuided Missile Cruiser
CGHGuided Missile Cruiser with an assigned Helicopter
CGNGuided Missile Cruiser, Nuclear Powered
CHCruiser with an assigned Helicopter
CLLight Cruiser
CLAAAnti-Aircraft Light Cruiser
CLCCommand Light Cruiser
CLDLight Cruiser, Dual-Purpose (AA and ASu)
CLGGuided Missile Light Cruiser - Light cruiser converted to carry missiles
CLGNGuided Missile Light Cruiser, Nuclear Powered
CLHHelicopter Light Cruiser - Cruiser with an assigned Helicopter
CLKLight Cruiser, ASW (Submarine Killer)
CLVAviation Cruiser
CMMinelayer, First Line (ex-cruiser)
CSScout Cruiser
CSGStrike Missile Cruiser
CSGNStrike Missile Cruiser, Nuclear Powered

The history of cruiser classification is somewhat complicated. Prior to 1920, there were three major classifications:

  • The categories of Protected Cruisers, Peace Cruisers, Third Class Cruisers and Unprotected Cruisers were all designated "C-X"
  • Armored Cruisers were designated "ACR-X"
  • Scout Cruisers were designated "CS-X"

where "X" was the hull series number.

There were also older and non-classified cruisers which had not been assigned classifications or hull numbers.

1920 to 1948

As part of the 20 July 1920 General Order No. 521 mentioned above, there were the following four major changes:

  • The Scout cruisers of the Salem and Omaha classes were merged into a single new category, Light Cruisers, and were given new hull series numbers CL-1 to CL-13.
  • Armored Cruisers formerly designated as "ACR-X" were now reclassified as "First Line Cruisers" and redesignated as "CA-X" with the same hull number as previously assigned.
  • All un-numbered cruisers were now classified into one of the above categories and received hull series numbers accordingly.
  • The newer Peace Cruisers were removed from the cruiser category entirely and were now reclassified as gunboats PG-27 through PG-34 and PG-36.

Some cruisers changed categories and hull series numbers as a result of this reorganization. For example, USS Minneapolis was previously designated as C-13 but was now designated as CA-17. Similarly, the former cruisers turned minelayers USS Baltimore (ex-C-3, now CM-1) and USS San Francisco (ex-C-5, now CM-2) were retained in the Cruiser category as "Minelayers, First Line."

In addition, Aircraft Carriers (CV) were also included in the "Cruiser" designation series as they were seen as part of the Scouting Forces, a role traditionally handled by cruisers. In other words, in General Order No. 521, the "C" in "CV" originally meant "Cruiser." Carriers were later moved into their own category and the "C" was then changed to mean "Carrier."

The Navy was not satisfied with the 1920 reclassifications, and so there was a second reclassification attempt on 8 August 1921. On this date, "First Line Cruisers" were again classified as "Armored Cruisers" and "Gunboats" PG-28 to PG-34 and PG-36 were again classified as cruisers, this time as light cruisers CL-16 to CL-23. This change left only USS Marblehead (PG-27, formerly C-11), still classified as a Gunboat. Also on this date, USS Olympia (CA-15) was reclassified as a light cruiser (CL-15) and it was intended for the old cruiser USS Chicago (CA-14) to be reclassified as a light cruiser (CL-14). Thus, these ships changed classification, but retained their previous hull numbers. Chicago was not actually redesignated and instead she was decommissioned in 1923 and became the uncommissioned barracks ship IX-5 at Pearl Harbor.

This classification system was used throughout the 1920s with the new 10,000 ton "Treaty" cruisers built during that time being commissioned into the CL hull number series, starting with USS Pensacola (CL-24). Then, as a result of the provisions of the London Conference of 1930, cruisers were split into two categories. The main differentiator was the size of the guns carried, with the Treaty Cruisers with 8" (20.3 cm) guns now being designated as "Heavy Cruisers" and those cruisers with smaller gun calibers being designated as "Light Cruisers." On 1 July 1931, this new classification was officially adopted by the USN and the meaning of the "CA" designation was changed from "Armored Cruiser" to "Heavy Cruiser." As a result of this reclassification, the "Treaty" cruisers USS Pensacola CL-24 through USS Portland CL-33 were redesignated as CA-24 through CA-33. Thus, these ships retained their previous Light Cruiser hull series numbers, even though the last Armored Cruiser, USS Charleston, was CA-19. As a result of these changes, the designations CA-20 through CA-23 were never used. From this time forward, all heavy and light cruisers built or planned between 1931 and 1949 used a single series of hull numbers, with the hull numbers interleaved between classes. This interleaving created somewhat of a jumble in the sequence of hull numbers in the latter part of World War II, when the light cruisers of the Juneau (ii), Cleveland, Fargo and Worcester classes and the heavy cruisers of the Baltimore, Oregon City and Des Moines classes were all being built simultaneously. The nuclear powered missile cruiser USS Long Beach, originally designated as CLGN-160, was the last ship to be numbered under this system, although she did not commission with this hull number, as noted below.

The Lexington class were the only battlecruisers ever laid down by the USN and were assigned hull series numbers CC-1 to CC-6. When construction was suspended following the Washington Naval Limitation Treaty of 1922, the first two of these ships were then completed as aircraft carriers USS Lexington CV-2 and USS Saratoga CV-3. The Alaska class of the 1940s were designated as Large Cruisers and assigned hull series numbers CB-1 to CB-6. The USN did not considered these ships to be battlecruisers.

1949 to 1974

In the late 1940s and 1950s, four new cruiser classification groups were created:

Anti-aircraft Cruisers
On 18 March 1949 anti-aircraft cruisers of the Atlanta (CL-51), Oakland (CL-95) and Juneau (ii) (CL-119) classes were redesignated as CLAA, but retained their previous light cruiser series hull numbers. An improved anti-aircraft cruiser class was cancelled in the 1940s and no other ships were ever given the CLAA classification.
ASW Cruisers
A planned class of Submarine Hunter-Killer Cruisers were designated CLK and numbered in a separate series, but only one ship of this type, USS Norfolk (CLK-1), was actually laid down and she was redesignated as destroyer leader DL-1 on 2 February 1951 prior to her commissioning on 4 March 1953.
Missile Cruisers
Two Baltimore class (CA-68) Heavy Cruisers and six Cleveland class (CL-55) Light Cruisers were converted into Guided Missile Cruisers in the late 1950s and early 1960s. These missile ships kept some of their large-caliber guns and started a new numeric series, but they retained their previous sub-type designations as either CAG-X (Heavy Missile Cruiser) or CLG-X (Light Missile Cruiser). The first of these conversions was USS Boston (CA-69) which was redesignated as CAG-1 on 4 January 1952, but she was not actually in commission as a missile cruiser until 1 November 1955. Three other Baltimore and Oregon City class heavy cruisers had all of their former gun armament and superstructures removed and were more heavily modified into all-missile cruisers. These three cruisers formed a single class (Albany) and were designated as CG-10 to CG-12. Two other planned conversions were cancelled and their hull numbers (13 and 14) were not reassigned. The nuclear powered missile cruiser USS Long Beach, originally designated as CLGN-160 and later as CGN-160, finally commissioned as CGN-9 on 9 September 1961.
Command Cruisers
Command Cruisers (later, Command Ships) had little armament but were equipped as fleet flagships with a great deal of command, control and communications facilities. USS Northampton (ex-CA-125) was launched as CLC-1 on 27 January 1951 and later redesignated as CC-1 on 15 April 1961. As noted above, prior to this time CC had been the designation for Battlecruiser. The light carrier USS Wright (CVL-47) was designated as CC-2 on 15 March 1962 and then converted into a Command Ship, recommissioning on 11 May 1963. It was planned to convert the Large Cruiser USS Hawaii (CB-3) into a large command cruiser and she was so redesignated as CBC-1 on 26 February 1952, but this conversion was later cancelled and she reverted back to her original designation on 9 October 1954.

Reflecting the obsolescence of their missile systems, on 1 May 1968 the Guided Missile Heavy Cruisers USS Boston (CAG-1) and USS Canberra (CAG-2) reverted back to their original Heavy Cruiser classifications CA-69 and CA-70, respectively, although they retained their Terrier missile launchers.

1975 to Present

The designations "Cruiser," "Destroyer" and "Frigate" were a source of some confusion in the USN during the early 1970s. Existing US carrier escorts were designated as Frigates (DLG and DLGN), but foreign warships of the size of US Frigates were generally classified as destroyers or cruisers. The USN was also applying the term "Patrol Frigate" or "PF" to the much smaller USS Oliver Hazard Perry class of convoy escorts then being designed. This usage was more in line with the "Frigate" designation as used in foreign navies, where it was usually given only to smaller warships of about the same size as the Perrys. On 30 June 1975, this issue was partially resolved when the following reclassifications were made:

  • Most DLG and DLGN Frigates were redesignated as Guided Missile Cruisers CG and CGN, with these warships retaining their original hull numbers (CG/CGN-16 through 40). This reclassification resulted in hull number CG-15 not being assigned. In addition, USS Arkansas, originally planned as DLGN-41, was commissioned on 18 October 1980 as CGN-41. An unnamed Virginia class nuclear cruiser, CGN-42, was cancelled in 1976 but then redesigned as a strike cruiser but again cancelled in 1978. She was redesigned but cancelled again in 1979 and then redesigned yet again before being finally cancelled in 1983.
  • Due to their smaller size, the Farragut class missile frigates (DLG-6 through DLG-15) were reclassified as Guided Missile Destroyers and given new hull numbers in that series (DDG-37 through DDG-46).
  • The remaining CLG cruisers that were still active or in reserve were redesignated as CG and retained their existing hull numbers.
  • Existing Guided Missile Escorts (DEG-1 to DEG-6) were redesignated as Guided Missile Frigates (FFG-1 to FFG-6) while those Escorts (DE) still in commission were redesignated as Frigates (FF) but retained their existing hull numbers. USS Oliver Hazard Perry herself was commissioned on 17 December 1977 as FFG-7.

This reclassification was incomplete, as the new Ticonderoga class Aegis missile ships were still planned to be designated as Guided Missile Destroyers (DDG-47 class), even though they were much larger vessels than the redesignated conventionally-powered cruisers (ex-DLG, now CG). Finally, on 1 January 1980, the Ticonderoga class DDGs were redesignated as CGs and Ticonderoga herself was commissioned on 22 January 1983 as CG-47. As the Ticonderoga class retained their originally planned hull numbers, this left a gap in the missile cruiser hull series sequence and hull numbers CG-43 to CG-46 were never assigned to any ship. There was some thought that these unused numbers could be assigned to the new generations of nuclear-powered missile cruisers then being discussed (the revamped CGN-42 and CSGN classes), but none of these ships were ever built. This redesignation of the early members of the Ticonderoga class also left a gap in the missile destroyer hull series sequence and hull numbers DDG-47 to DDG-50 were not reassigned to any ship. USS Arleigh Burke, the first of a new class of missile destroyers, was commissioned on 4 July 1991 as DDG-51.

Torpedo Boats, Destroyers, Escorts and Frigates

BDEDestroyer Escorts to be transferred to Britain during World War II
CGDestroyers loaned to the Coast Guard during 1924-1934
DDestroyer (prior to 1921)
DDDestroyer (after 1921)
DDCASW Corvette
DDEDestroyer converted to Fleet Escort
DDGGuided Missile Destroyer
DDHDestroyer with an assigned Helicopter
DDKDestroyer, ASW (Submarine Killer)
DDRDestroyer, Radar Picket
DEDestroyer Escort, Escort or "Ocean Escort"
DECDestroyer Escort, Control (Amphibious Control)
DEGDestroyer Escort, Guided Missile
DERDestroyer Escort, Radar Picket
DLDestroyer Leader (1920 to 1955)
DLFrigate (after 1955)
DLGFrigate, Guided Missile
DLGNFrigate, Guided Missile, Nuclear Powered
EDDDestroyer, Experimental Test Ship (before 2005)
EDDDestroyer, Self-Defense Test Ship (after 2005)
EDDEExperimental Escort Destroyer
EDDGGuided Missile Destroyer, Experimental Test Ship
FFGGuided Missile Frigate
FFHFrigate with an assigned Helicopter
FFRRadar Picket Frigate
FFTReserve/Training Frigate
PEPatrol Escort
PFFrigate or Patrol Frigate
PFGPatrol Frigate, Guided Missile
TBTorpedo Boat

The United States built her first torpedo boat Cushing (TB-1) in 1890 and her last Wilkes (TB-35) in 1902. Most of these were decommissioned or re-purposed prior to the start of World War I. The surviving Torpedo Boats were renamed on 01 August 1918 as "Coast Torpedo Boat #X" where "X" was a new numeric series, starting with # 1. This number was given to the former USS Foote (TB-3) which was now renamed as USS Coast Torpedo Boat # 1 (TB-3). Like the old pre-dreadnought battleships mentioned above, this renaming of torpedo boats was done in order to free up their names for new destroyers. All of these torpedo boats were decommissioned the following year and soon afterwards sold for scrap. As these boats were all gone prior to the 17 July 1920 redesignation, the Torpedo Boat designation went out of service and was not replaced with a new one. New small warships of about this size were now designated in the Patrol Vessel category.

The first USN destroyer was Bainbridge (D-1) which completed in 1902. The designation for all existing destroyers was changed from "D-X" to "DD-X" as part of the 20 July 1921 redesignation mentioned above. During prohibition, twenty-five destroyers were loaned to the US Coast Guard and these ships were redesignated as "CG-X" starting with USS Cassin (DD-43) which became CG-1 on 7 June 1924. Most of these destroyers were scrapped following their return to the USN after the end of prohibition but a few were retained and these few were given back their previous DD designation and hull number.

Following World War II, many Fletcher (DD-445), Allen M. Sumner (DD-692) and Gearing (DD-710) class destroyers were modified and given new, specialized missions as Fleet Escorts (DDE), Radar Pickets (DDR) and ASW submarine killers (DDK). The ASW destroyers (DDK) were redesignated as Fleet Escort destroyers (DDE) on 4 March 1950. All Fleet Escort destroyers (DDE) were reclassified as destroyers (DD) on 30 June 1962. Most radar picket destroyers (DDR) were reclassified as destroyers (DD) during the 1960s. One Fleet Escort destroyer USS Saufley (DDE-465) was reclassified as an Experimental Escort Destroyer (EDDE) on 1 January 1951 and then used as a test bed during the 1950s for sonar and ASW experiments. She was reclassified as a general purpose destroyer (DD-465) on 1 July 1962.

Faced with a growing Soviet submarine threat, several conversions of the Benson/Livermore (DD-421/DD-429) classes to an ASW "corvette" (DDC) design were proposed for FY1955. This would have entailed removing one boiler and a five-inch gun so as to increase tankerage and ASW capabilities. Nothing came of these proposals and most of these ships remained decommissioned until they were scrapped in the late 1960s and early 1970s.

USS Gyatt (DD-712) was modified to carry a twin Terrier launcher and she was designated as DDG-712 on 1 December 1956. She was redesignated as DDG-1 on 23 May 1957. Her missile emplacement was later removed and her designation reverted back to DD-712 on 1 October 1962.

The "DL" designation meaning "Destroyer Leader" was originally created as part of the 17 July 1920 designation system revision. This designation was not assigned to any ship prior to 2 February 1951 when the ASW cruiser USS Norfolk CLK-1 was redesignated as DL-1 as described above. In addition, the new fleet destroyers of the Mitscher class, which were originally designated in the DD series as DD-927 to DD-930, were redesignated on 2 February 1951 as DL-2 to DL-5. This designation change was meant to indicate that these warships were significantly larger than those destroyers built during World War II yet still smaller than cruisers. As these warships were not really "leaders" in the sense of being equipped as destroyer flotilla leaders, the DL designation was reauthorized to mean "Frigate" on 1 January 1955.

The follow-on Farragut class frigates were originally to be an all-gun design and the first three ships of this class were designated as DL-6 to DL-8. The next three ships starting with USS Coontz were to a similar design but were given a Terrier missile launcher and were designated accordingly as DLG-1 to DLG-3. However, the Navy subsequently decided to equip the Farragut class with Terrier missile launchers and their designation was then changed to become DLG-6 to DLG-8 on 14 November 1956. USS Coontz and her sisters were renumbered in sequence starting with DLG-9 on that same date. As a result of these changes, all DL and DLG warships were in the same hull number series.

The Mitscher class frigates Mitscher (DL-2) and John McCain (DL-3) were converted to carry a Tartar missile launcher during the 1960s and they were then redesignated as missile destroyers DDG-35 and DDG-36, respectively, in 1968-69. As noted above in the cruiser section, on 30 June 1975 most Frigates were redesignated as CG and CGN with the same hull number as used previously, the exception being the Farragut DLG class which were redesignated as missile destroyers DDG-37 through DDG-46.

The designation "DE" was originally assigned to the Destroyer Escorts of World War II. The "DE" designation was changed to mean "Ocean Escorts" for those convoy escorts of the 1950s-1970s starting with the USS Dealey (DE-1006) class and ending with the USS Knox (DE-1052) class, but this was a seldom-used term. The DANFS entry for USS Knox herself describes her as "the prototype in a new class of destroyer escorts" while the Naval Vessel Register (NVR) currently lists all DE-designated ships as simply "Escort" including those built during World War II. As stated above, existing Guided Missile Escorts (DEG) were redesignated as Guided Missile Frigates (FFG) and those Escorts (DE) still in commission were redesignated as Frigates (FF) on 30 June 1975.

Some Edsall (DE-129) class destroyer escorts were converted to Radar Picket (DER) ships during the 1950s. They carried this designation during the rest of their careers, although none of them appear to have been used in that role after about 1960. As part of the 30 June 1975 reclassification program described above, two of these ships, USS Camp (DER-251) and USS Forster (DER-334) were redesignated as Radar Picket Frigates FFR-251 and FFR-334, respectively. These two ships had been transferred to the Republic of Vietnam during the 1970s. When that nation fell at the end of the Vietnam War, Camp escaped to the Philippines but Forester was captured on 30 April 1975 and so was not under USA control at the time of her redesignation two months later.

Three Destroyer Escorts (DE-698, DE-704 and DE-705) were converted to Amphibious Control Ships (DEC) in 1950-51 by adding extra communications gear, but they were all placed back into reserve by 1954 and the designation was abolished in 1957. The amphibious control role was taken over by the APD flagships.

The "PF" designation was originally used for World War II frigates of the Asheville (PF-1) and Tacoma (PF-3) classes. In the 1970s, it was proposed to designate what became the Oliver Hazard Perry (FFG-7) class as PF which would have then meant "Patrol Frigates." In the end, these ships were designated simply as "Frigates."

During the late 1960s and early 1970s, a series of design studies were made for the "next generation" of ASW and guided missile carrier escorts. These warship designs were given various interim designations, such as "DX" for the conventionally powered ASW destroyers, "DXG" for conventionally powered guided missile destroyers, "DXGN" for nuclear powered guided missile destroyers and "DG/Aegis" for an "austere" Aegis missile destroyer. These proposals coalesced around what eventually became the conventionally powered Spruance (DD-963) ASW destroyers and Ticonderoga (CG-47) Aegis missile cruisers. The nuclear powered version, which had grown considerably in size and was now known as a "Strike Cruiser" or CSGN and then later as the "CGN-42" class, was cancelled in the fall of 1978 although it was resurrected a few times until being cancelled once and for all in 1983.

A similar series of interim designations was used for new destroyer and cruiser designs during the early 2000s, respectively "DD-21" and "CG-21" until these temporary ones were replaced with the formal "DD(X)" and "CG(X)" designations. The first destroyer in the DD(X) series was christened as USS Zumwalt (DDG-1000). This meant that these ships are numbered in the DD series, rather than the DDG series, and it appears likely that the unused hull numbers DD-998 and DD-999 will not be assigned to any ship. As of this time (2019), no CG(X) cruisers have been funded or laid down.

As expected, the schedule delays and ballooning costs of the Zumwalt class destroyers has resulted in additional orders for Arleigh Burke DDGs and it is now expected that advanced versions of this class will continue in production for at least the next decade.

The DD designation went out of service when "the last destroyer" USS Cushing DD-985 was decommissioned on 21 September 2005. As noted above, the first US Torpedo Boat (TB-1) was also named Cushing.

In January 2015 the Navy announced that new ships in the Freedom (LCS-1) and Independence (LCS-2) classes would now be designated as Frigates (FF). However, Navy later decided to discontinue building new LCS ships and will dispose of those they do have. As of 2021, no frigates are in commission in the USN, but it is planned to start construction in the summer of 2021 of a new FFG class, the USS Constellation (FFG-62) type.


AGSSAuxiliary/Experimental Submarine
APSAuxiliary Cargo Submarine
NSSNNew Nuclear Powered Attack Submarine (temporary designation)
SSubmarine (Attack/Fleet) - prior to 1920
SSSubmarine (Attack/Fleet) - after 1920
SCCruiser Submarine
SFFleet Submarine
SMSubmarine, Minelayer
SSAAuxiliary/Experimental Submarine
SSAGAuxiliary/Experimental Submarine
SSBSubmarine, Ballistic Missile
SSBNSubmarine, Ballistic Missile, Nuclear Powered
SSGAttack Submarine, Guided Missile
SSGNAttack Submarine, Guided Missile, Nuclear Powered
SSKHunter-Killer Submarine
SSMMidget Submarine
SSNAttack Submarine, Nuclear Powered
SSPTransport Submarine
SSRRadar Picket Submarine
SSRNRadar Picket Submarine, Nuclear Powered
SSTSubmarine, Target/Training

Early submarines were given the designation "Submarine Torpedo Boats" (later shortened to just "Submarine") and most were given fish names. On 17 November 1911 these names were discontinued and in their place was substituted an alphanumeric designation system representing their class and sequence. For example, USS Bonita (S-15) was renamed as USS C-4 (S-15), with C-4 meaning that she was a member of the third class of USN submarines and the fourth submarine of that class. Newer classes of submarines generally followed the letters of the alphabet, with "S" being the last letter used during the building spree generated by World War I.

Special note should be made here of the only US ship with a "half" hull number, the submarine USS Seal / G-1 which was assigned hull number S-19 ½, apparently because the Navy did not want her and thought that she would not be approved for service. She was eventually redesignated as S-20 sometime prior to her decommissioning on 6 March 1920. This was a reuse of the hull number previously assigned to USS F-1 which had been lost in a collision on 17 December 1917.

Following the reclassification of 1920, all of the older submarines changed their hull series number designation from S to SS, but new submarines built during the mid-1920s to 1931 period were separated into different hull number series, depending upon their assigned role. Fleet Submarines (SF) were intended to scout ahead of the battle fleet, Cruiser Submarines (SC) were larger boats with heavy gun armament while the single Minelayer Submarine (SM) had special tubes for launching mines. All of these newer submarines were given "V" alphanumeric names, although most of them were to differing designs.

This rather confusing practice of giving submarines both an alphanumeric name and an alphanumeric designation was continued until 1931. In that and the following year, all of the submarines built since the mid-1920s were given fish names and redesignated into the SS hull number series. The older submarines built during and immediately after World War I continued with their alphanumeric names (mainly the O, R and S classes). New submarines built since 1931 have continued to be designated into the SS numeric series, with a few exceptions, as detailed below.

In a reprise of the alphanumeric naming of the 1911 to 1931 period, Training and Hunter-Killer submarines of the 1950s originally had only an alpha-numeric designation instead of a hull number. Training submarine SST-1 was commissioned as "T-1" and SST-2 was "T-2." On 15 May 1956 these training submarines were given fish names but they retained their SST designations and hull numbers throughout their service lives. In a similar fashion, the "Hunter-Killer" ASW submarines SSK-1, SSK-2 and SSK-3 of that period were also given only alphanumeric names, "K-X" with the X being the same number as in their hull designations. On 15 December 1955, these three boats were given standard fish names and on 15 August 1959 they were renumbered into the SS series.

The modern Seawolf class submarines were designated as SSN-21 to SSN-23, with this apparently meaning "21st century" submarine. This designation seems to have been an aberration, as the follow-on Virginia class submarines continue the previous series, starting at SSN-774.

Some former Ohio (SSBN-726) class ballistic missile submarines were converted during the early 2000s into Tomahawk-carrying guided missile submarines (SSGN).

Amphibious Forces

AGCAmphibious Fleet Flagship
INLSImproved Navy Lighterage System
LC(FF)Landing Craft, Flotilla Flagship
LCALanding Craft, Assault
LCACLanding Craft, Air Cushion
LCCAmphibious Command Ship
LCILanding Craft, Infantry
LCI(G)Landing Craft, Infantry, Gun
LCI(L)Landing Craft, Infantry, Large
LCI(R)Landing Craft, Infantry, Rocket
LCMLanding Craft, Mechanized
LCM/MLLanding Craft, Mechanized, Minelaying
LCPLanding Craft, Personnel
LCPLLanding Craft, Personnel, Large
LCPNLanding Craft, Personnel, Nested
LCPRLanding Craft, Personnel, Ramped
LCRLanding Craft, Rubber or Riverine
LCSLanding Craft, Support (prior to 2004)
LCS(L)Landing Craft, Support, Large (Rocket)
LCTLanding Craft, Tank
LCULanding Craft, Utility
LCVLanding Craft, Vehicle
LCVPLanding Craft, Vehicle and Personnel
LCWLanding Craft, Wing-in-Ground-Effect
LFRInshore Fire Support Ship
LFSAmphibious Fire Support Ship
LHAAmphibious Assault Ship, General Purpose
LHDAmphibious Assault Ship, Multi-purpose
LKAAmphibious Cargo Ship
LPAAmphibious Transport
LPDAmphibious Transport Dock Ship
LPHAmphibious Assault Helicopter Carrier
LPRAmphibious Transport, Small
LPSSAmphibious Transport, Submarine
LSDDock Landing Ship
LSMLanding Ship, Medium
LSM(R)Landing Ship, Medium, Rocket
LSSLanding Ship, Support
LSSLLanding Ship, Support, Light
LSTLanding Ship, Tank
LSTHLanding Ship, Tank, Evacuation (Hospital)
LST/MLLanding Ship, Tank, Minelaying
LSULanding Ship, Utility
LSVLanding Ship, Vehicle
LWTAmphibious Warping Tug
MPFUBMaritime Prepositioning Force Utility Boat

Most of the larger "Landing Craft" of World War II were later reclassified as "Landing Ships."

Navy Expeditionary Craft
EODExplosive Ordnance Disposal Craft (11 meter rigid hull inflatable boat)
MK VI PBMark VI Patrol Boat
MERCMulti-use EOD Response Craft
PB 3434-foot Patrol Boat
RCBRiverine Command Boat
RPBRiverine Patrol Boat

These are craft which are capable of missions including patrol, over-watch and enemy denial in harbor, riverine and littoral areas.

Special Warfare Craft
CCACombatant Craft Assault
CCHCombatant Craft Heavy
CCMCombatant Craft Medium
DSB36-foot Dive Support Boat
LSSCLight Seal Support Craft
MSSCMedium Seal Support Craft
NSW RHIBNSW Rigid Hull Inflatable Boat
SOC-RSpecial Operations Craft – Riverine
SDVSwimmer Delivery Vehicle (before 2016)
SDVSeal Delivery Vehicle (after 2016)
SSCSurface Support Craft
SWCLSpecial Warfare Craft, Light
SWCMSpecial Warfare Craft, Medium
SWCSShallow Water Combat Submersible

Littoral Warfare Ships

ASPBAssault Support Patrol Boat
ATCTroop Carrier, Armored
CCBCommand and Control Boat
FCSFast Sea Frame
LCSLittoral Combat Ship (after 2004)
PACVPatrol Craft, Air Cushion
PBPatrol Boat
PBLAmphibious Assault Patrol Boat
PBMRiverine Monitor, Multi-purpose
PBRRiver Patrol Boat
PCCoastal Patrol Craft/Submarine Chaser (173 ft)
PCCSubmarine Chaser, Control
PCESubmarine Chaser or Patrol Escort
PCECPatrol Escort, Control
PCERPatrol Escort, Rescue
PCFPatrol Craft, Inshore
PCHPatrol Craft, Hydrofoil
PCIFast Coastal Interceptor
PCSSubmarine Chaser (136 ft)
PCSCSubmarine Chaser (Control)
PEEagle Boat (steel patrol craft)
PGPatrol Gunboat or Corvette
PGMPatrol Gunboat, Missile
PGHPatrol Craft, Hydrofoil
PHHydrofoil Gunboat
PHMMissile Hydrofoil
PHTHydrofoil Torpedo Boat
PLHigh Endurance Cutters
PMMedium Endurance Cutters
PRRadar Picket Conversion
PSOCSpecial Operations Patrol Craft
PTPatrol Torpedo Boat
PTCPatrol Motor Boat Submarine Chaser
PTFPatrol Craft, Fast
PWWing-in-Ground-Effect Patrol Craft
PYPatrol, former Yacht
PYeCoastal Patrol, former Yacht
SCSubmarine Chaser (110 ft)
SCCSubmarine Chaser (Control)

The "PG" designation was given both to patrol gunboats built in the US during the first half of the twentieth century and to corvettes transferred from the Royal Navy under reverse lend-lease in 1942.

Many of the "Monitor," "Patrol Boat" and "Patrol Craft" designations were assigned during the Vietnam War. The end of that war retired these designations.

The "LCS" designation was originally assigned during World War II to "Landing Craft, Support." In 2004, the USN reassigned this designation to the "Littoral Combat Ship" for the Freedom (LCS-1) and Independence (LCS-2) classes. In January 2015 the Navy announced that new ships in these classes would now be designated as Frigates (FF). However, Navy later decided to discontinue building new LCS ships and to replace them with a new FFG design.

Mine Warfare Ships

ACMAuxiliary Minelayer
AMcCoastal Minesweeper
AMc(U)Coastal Minesweeper (underwater locator)
AMSMotor Minesweeper
BAMMinesweeper built for Britain under Lend-Lease
BYMSMotor Minesweeper built for Britain under Lend-Lease
CMMinelayer, First Line (before 1941)
CMMinelayer, Fleet (after 1941)
CMcMinelayer, Coastal (before 1958)
DMPrior to 1955 - Light Minelayer (converted destroyer)
DMAfter 1955 - Destroyer Minelayer (converted destroyer)
DMSHigh Speed Minesweeper (converted destroyer)
MCACAir Cushion Mine Countermeasures Craft
MCDMine Countermeasures Drone
MCMMine Countermeasures Ship
MCSMine Countermeasures Support Ship
MCTMine Countermeasures Conversion Trainer
MHCCoastal Minehunter
MHIInshore Minehunter
MMFleet Minelayer (1955)
MMCCoastal Minelayer
MMDFast Minelayer (ex-DM destoyers)
MMFFleet Minelayer (after 1955)
MSAAuxiliary Minesweeper
MSACMinesweeper, Air Cushion
MSCMinesweeper, Coastal (after 1958)
MSCOMinesweeper, Coastal, Old
MSDMinesweeper, Drone
MSFMinesweeper, Fleet, Steel Hull
MSHMinesweeper, Harbor
MSIMinesweeper, Inshore
MSOMinesweeper, Ocean
MSRMinesweeper, River
MSSMinesweeper, Special Device
YMSMinesweeper, Motor

As noted above in the Cruiser section, the "CM" designation was originally given to the ex-cruisers USS Baltimore (CM-1) and USS San Francisco (CM-2) which were converted to minelayers but retained in the cruiser category.

Those Benson and Gleaves class destroyers converted to minesweepers (DMS) during World War II were reclassified as destroyers (DD) during 1954/1955.

Starting in 1955 the Navy started using "M" as the first letter in the designations for Minewarfare ships and many ships changed designations as a result. The following types were reclassified on 7 February 1955:

  • Minesweepers (AM) were redesignated either as Fleet Minesweepers, Steel Hull (MSF) or as Ocean Minesweepers (MSO).
  • Motor Minesweepers (AMS) were redesignated as Coastal Minesweeper, Old (MSCO).
  • Auxiliary Minelayers (ACM) were redesignated as Auxiliary Minelayers (MMA).
  • Fleet Minelayer USS Terror (CM-5) was redesignated as Fleet Minelayer (MM-5). Her designation was changed again to Fleet Minelayer (MMF-5) in October 1955.
  • The USS Robert H. Smith (DM-23) class Light Minelayers (converted Allen M. Sumner class destroyers) were redesignated as Destroyer Minelayers (DM). These ships were later redesignated as Fast Minelayers (MMD) on 1 January 1969.

Auxiliary Ships

ABCrane Ship (later changed to ACS)
ACCollier (coaling ship)
ACSCrane Ship
ADDestroyer Tender
ADCDry Cargo Replenishment Ship
ADGDegaussing Vessel
AEAmmunition Ship
AFRefrigerated Stores Ship
AFDBLarge Floating Drydock
AFDLSmall Floating Drydock
AFDMMedium Floating Drydock
AFSCombat Stores Ship
AGAuxiliary, Generic/General (miscellaneous) use
AGDSeagoing Dredger
AGDEExperimental Destroyer Escort
AGDSDeep Submergence Support Ship
AGEHHydrofoil Research Ship
AGERExperimental Research Ship
AGFFleet Flagship
AGFFExperimental Frigate
AGHHelicopter Support Ship
AGIIntelligence Gathering Ship
AGLLighthouse Tender
AGMMissile Range Instrumentation Ship
AGMRCommunications Major Relay Ship
AGOROceanographic Research Ship
AGOSOcean Surveillance Ship
AGPPatrol Craft Tender
AGRRadar Picket Ship (converted cargo ship)
AGSSurveying Ship
AGScSurveying Ship, Coastal
AGTRTechnical Research Ship
AHHospital Ship
AHRHospital Ship, Riverine
AKCargo Ship
AKACargo Ship, Attack
AKDCargo Ship, Dock
AKEDry Cargo Ship
AKLLight Cargo Ship
AKNNet Cargo Ship
AKRCargo Ship, Roll-on/Roll-off
AKSGeneral Stores-issue Ship
AKVAircraft Cargo Ship or Ferry
ANNet Laying (Net Tender) Ship
ANLNet Laying (Net Tender) Ship
AOFleet Oiler
AOEFast Combat Support Ship
AOGGasoline Tanker
AOLSmall Oiler
AORReplenishment Oiler
AORLSmall Replenishment Oiler
AOTTransport Oiler
APPersonnel Transport Ship
APAAttack Personnel Transport Ship
APBBarracks Ship, Self-propelled
APCCoastal Transport
APDTroop Transport (High Speed)
APHTroop Transport, Hospital
APLFloating Barracks
APMMechanized Artillery Transport
APRRescue Transport
APVAircraft Transport
ARRepair Ship
ARBRepair Ship, Battle Damage
ARCRepair Ship, Cable
ARGRepair Ship, Internal Combustion Engine
ARDRepair Dock
ARDMMedium Repair Dock
ARLRepair Ship, Landing Craft
ARSSalvage Ship
ARSDSalvage Ship, Lifting Vessel
ARSTSalvage Ship, Tender
ARVAircraft Repair Ship
ARVAAircraft Airframe Repair Ship
ARVEAircraft Engine Repair Ship
ASSubmarine Tender
ASESubmarine Ammunition Ship
ASRSubmarine Rescue Vessel
ATAAuxiliary Ocean Tug
ATFFleet Tug
ATGBLarge Icebreaking Tug
ATRRescue Tug
ATSSalvage Tug
AVSeaplane Tender
AVBAviation Logistics Support Ship
AVCCatapult Lighter
AVDAviation Tender (Converted Destroyer)
AVPSmall Seaplane Tender
AVSAviation Supply Ship
AVTAuxiliary Aircraft Transport
AWDistilling Ship
AWKWater Tanker
AXTraining Vessel (Current meaning)
Auxiliary Tender, Large (Former meaning)
AXSSail Training Vessel
AYVIP Yacht (Current meaning)
Auxiliary Tender, Small (Former meaning)
AZAerostat Tender
FDLFast Deployment Logistics Ship

Attack Cargo (AKA) and Attack Personnel Transport (APA) ships differ from Cargo (AK) and Personnel Transport (AP) ships by being specially equipped to partake in amphibious landings. The AKA and APA designations were replaced by LKA and LPA as of 1 January 1969.

Despite having been captured in 1968, USS Pueblo (AGER-2) officially remains in commission as of this date (2019).

Support Craft

AFSBAfloat Forward Staging Base Interim
DSRVDeep Submergence Rescue Vehicle
DSVDeep Submergence Vehicle
IXUnclassified Miscellaneous
IXSSUnclassified Miscellaneous Submarine
JHSVJoint High Speed Vessel
MLPMobile Landing Platform
NRNuclear Powered Research Submersible
SBXMobile Radar
SDVSwimmer Delivery Vehicle
SLWTSide Loading Warping Tug
TWRTorpedo Retriever
WLBSeagoing Buoy Tender
WLMCoastal Buoy Tender
WLIInland Buoy Tender
WLICInland Construction Tender
WLRRiver Buoy Tender
X-1Midget Submarine (research vessel)
YAAsh Lighter
YAGMiscellaneous Service Craft
YC1921: Coal Barge
YCafter about 1935: Lighter
YCDFueling Barge
YCFCar Float
YCVAircraft Transportation Lighter
YDFloating Crane or Derrick
YDTDiving Tender
YEAmmunition Lighter
YFCovered Lighter or Frieght Lighter
YFNCovered Lighter
YFNBLarge Covered Lighter
YFNDDry Dock Companion Craft
YFNXSpecial Purpose Lighter
YFPPower Barge
YFRTRange Tender
YFUHarbor Utility Craft
YGGarbage Barge
YGNGarbage Barge
YHAmbulance Boat
YHLCSalvage Lift Craft, Heavy
YHTHeating Scow
YLCSalvage Lift Craft
YMDMud Scow
YMLCSalvage Lift Craft, Medium
YNGGate Craft
YOOil Barge
YOGGasoline Barge
YOGNGasoline Barge
YONOil Barge
YOSOil Storage Barge
YPSeamanship Training Craft
YPDPile Driver
YPRParasail Training Craft
YRRepair Barge
YRBRepair and Berthing Barge
YRBMRepair, Berthing and Messing Barge
YRDHHull Repair Barge
YRDMMachinery Repair Barge
YRMMissile Retriever
YRRRadiological Repair Barge
YRSTSalvage Craft Tender
YRTTorpedo Retriever
YSStevedoring Barge
YSRSludge Removal Barge
YTHarbor Tug
YTBLarge Tug
YTLSmall Tug
YTMMedium Tug
YTTTorpedo Trials Craft
YVSeaplane Barge
YWWater Barge
YWNWater Barge
YWOWaste Oil Barge

AFSB, JHSV and MLP were reclassified as ESB, EPF and ESD, respectively, in September 2015. These ships are now listed below in the Expeditionary Forces section.

Expeditionary Forces

EPFExpeditionary Fast Transport
ESBExpeditionary Sea Base
ESDExpeditionary Transfer Dock

The EPF, ESD and ESB ships were originally called the Joint High Speed Vessel (JHSV), Mobile Landing Platform (MLP) and the MLP Afloat Forward Staging Base (AFSB), respectively. In September 2015, the Secretary of the Navy re-designated these hulls to conform to traditional three-letter ship designations.

These ships are part of the Military Sealift Command and are therefore designated as USNS rather than USS for that reason. Military Sealift Command vessels usually have civilian crews.

Old Ships

OBBBattleship, Second Line
OCCBattle Cruiser, Second Line
OCACruiser, Second Line
OCLLight Cruiser, Second Line
OCMMinelayer, Second Line
OCVAircraft Carrier, Second Line
ODDDestroyer, Second Line
OSSSubmarine, Second Line
OSFFleet Submarine, Second Line

As part of the 17 July 1920 redesignation system, a series of "old ship" or "second line" designations was created in order to distinguish between front line ships and those that were past their prime. As far as I have been able to determine, it would appear that these were not officially assigned to any ship. This may have been a result of these old ships being scrapped as a result of the downsizing of the fleet following the end of World War I and the adoption of the Washington Naval Limitation Treaty.

Plan Orange Conversions

XAV Seaplane Carrier, converted
XAVP Small Seaplane Carrier, converted
XCV Aircraft Carrier, converted

During the 1920s and 1930s Plan Orange included mobilization and conversion of various merchantmen and liners into auxiliary warships. The number of suitable ships fluctuated throughout this period as older ships went to the breakers and newer ships were placed into service. As of April 1939, ships available for conversions would have added five "fleet" carriers (none capable of more than 24 knots), two seaplane tenders and eight small seaplane tenders to the rolls. These plans were all abandoned in November 1940, mainly because the conversions would have tied up too much shipyard capacity for little real gain.

USS Constitution

The two hundred year-old USS Constitution is unique in that she is the only commissioned ship in the USN that does not have a classification other than her name. The Secretary of the Navy, J. William Middendorf, II, ordered her reclassification from "IX-21" to "None" effective as of 1 September 1975. She is now listed on the Naval Vessel Register (NVR) of active in-commission ships only by her name.

U.S. Navy Ship Designations and Naming

Page History

14 May 2007 - Benchmark
17 March 2009 - Added comments regarding redesignations of Mitscher class missile destroyers and extension of Arleigh Burke class DDG
17 September 2010 - Added "Old Ship" section and added information on Farragut class DLG designations
14 February 2014 - Added note about CV designation going out of use, minor changes for clarity in the cruiser and destroyer sections
01 June 2014 - Added DEC and description
30 March 2015 - Noted change from LCS to FF designation for new construction, added CVT to the Aircraft Carrier category and AFSB, JHSV and MLP to the Support Craft category, added note about Torpedo Boat renaming and corrected typographical error
14 May 2015 - Minor corrections for clarity, added SBX and YWO to Support Craft and added a mention of USS Seal / G1
20 January 2016 - Added note regarding transfer of destroyers to the US Coast Guard during prohibition
23 April 2016 - Converted to HTML 5 format
18 May 2016 - Added to the Support Craft category, added information to Minewarfare section and updated active designations for 2016
17 February 2018 - Minor changes for clarity
28 April 2018 - Added DDC type and description
09 August 2018 - Added CVHA and CVU types
17 October 2018 - Added FFR type and description
04 March 2019 - Corrected typographical error, added Expeditionary Forces section
26 June 2019 - Added EDDG type, many new auxiliary, littoral and patrol designations from the Vietnam era, new Navy Expeditionary Craft / Special Warfare Craft section, comments about meaning of "C" in "CV", the captures of ex-USS Forester and USS Pueblo, First Line Cruiser and Cruiser Minelayers, added comments and link to SECNAVINST 5030.8C, corrected hull number of USS Cushing, typographical error and updated links to off-site USN History webpages
15 May 2021 - Changed FF designation to inactive, added comment about new FFG-62 class, changed LCAC designation to active