Table of Contents
S T U V W X  Y  Z

--- X ---

 X -- Prefix in standard Navy aircraft designation, designating an experimental model

 X -- Any punctuation (dispatches)

(X) -- Pre-Flight Center under reserve Training (not a Reserve Station)

 X -- A suffix, which, when appended to a basic USNR line officer classification, indicates special qualifications in electronics: officers who, in addition to having the qualifications for CIC Watch Officers, are qualified in aircraft control except at night or in conditions of low visibility.

 XAM -- Merchant ship converted into a mine-sweeper (old designation)

 XAP -- Merchant cargo ship

 XAP -- Radio Communications Team

 XAP -- Transport (GB)

 XB -- Halifax to Boston (routing designation)

 XCL -- Armed Merchant Cruiser (US)

 X&D Flot -- Experiment and Development Flotilla (landing Craft)

 XFM -- Expeditionary Force Message (usually EFM)

 XMTR -- Transmitter

 XO -- Executive Officer

 XPC -- OG cutter assigned to Inshore Patrol

 XPG -- Converted merchant ships, assigned to antisubmarine patrol or convoy escort

 Xray -- "X" in the phonetic alphabet

 XRP -- X-Ray and Photofluorography Technician

 XRT -- X-Ray Technician

--- Y ---

 Y -- Consolidated Aircraft Corporation (manufacturer's symbol)

 Y -- Consolidated-Vultee Aircraft Corporation (manufacturer's symbol)

 Y -- Tankers (Army symbol)

 Y -- Yeoman

 YA -- District Lighter, Ash

 YAG -- District Auxiliary, Miscellaneous

 YandD -- Bureau of Yards and Docks

 YangPat -- Yangtze Patrol, Asiatic Fleet

 Yar -- Yarron (boilers)

 YC -- District Lighter Open

 YC -- Yard Craft

 YCK -- Open Cargo Lighter

 YCU -- Aircraft Transportation lighter

 YCV -- District Lighter, Aircraft Transportation

 Y&D -- Bureau of Yards and Docks

 YD -- District Derrick, Floating

 YDG -- District Degaussing Vessel

 YDSD -- Yards & Docks Supply Depot

 YDT -- District Diving Tender

 YE -- Aircraft radio homing beacon (HAYRAKE)

 YE -- District Lighter, Ammunition

 YF -- District Lighter, Covered (self-propelled)

 YF -- Provision Store Lighter

 YF -- Range Tender

 YFB -- District Ferry Boat or Launch

 YFC -- Car Float

 YFD -- Floating Drydock

 YFN -- District Lighter, Covered (non self-propelled)

 YFR -- Covered Lighter, Refrigerated (self-propelled)

 YFRN -- Covered Lighter, Refrigerated (non self-propelled)

 YFT -- District Lighter, Torpedo Transportation

 YG -- District Lighter, Garbage, (self-propelled)

 YG -- Land-based radio homing beacon (MOTHER)

 YGN -- District Lighter, Garbage (non self-propelled)

 Y-gun -- Y-type depth charge projector

 YH -- District Lighter, Ambulance

 YH -- Radar beacon

 YHB -- District Boat, House

 YHT -- District Scow, Heating

 YJ -- Radar homing beacon

 YK -- Radar beacon

 YLA -- District Lighter, Open Landing

 YM -- District Dredge

 YM -- Radar beacon

 YMS -- District Motor Mine Sweeper

 YMT -- District Tug, Motor

 YN -- District Net Tender

 YNG -- District Gate Tender

 YNT -- District Net Tender (Tug Class)

 YO -- District Barge, Fuel Oil (self-propelled)

 YOG -- District Barge, Gasoline (self-propelled)

 YOGN -- District Barge, Gasoline (non self-propelled)

 Yoke -- "Y" in the phonetic alphabet

 YON -- District Barge, Fuel Oil (non self-propelled)

 YOS -- District Barge, Oil Storage

 YP -- District Patrol Vessel

 YPD -- District Floating Pile Driver

 YPK -- District Barge, Pontoon Stowage

 YR -- District Workshop, Floating

 YRC -- District Chamber, Submarine Rescue

 YRD(H) -- District Workshop, Floating, Drydock (Hull)

 YRD(M) -- District Workshop, Floating, Drydock (Machinery)

 YS -- District Barge, Stevadoring

 YSD -- District Derrick, Seaplane Wrecking

 YSP -- District Pontoon Salvage

 YSR -- District Barge, Sludge Removal

 YT -- Harbor Tug

 YT -- Yukon Territory

 YTB -- District Tug, Harbor, Big

 YTL -- District Tug, Harbor, Little

 YTM -- District Tug, Harbor, Medium

 YTT -- District Barge, Torpedo Testing

 YTX -- Planned District Craft

 YW -- District Barge, Water (self-propelled)

 YWN -- District Barge, Water (non self-propelled)

--- Z ---

 Z -- Administrative Aircraft (suffix to plane designation)

 Z -- Lighter-than-air aircraft (airship)

 Z -- Impedance (radar)

 ZD -- Zone Description

 Zebra -- "Z" in the phonetic alphabet, replacing the obsolete "Zed"

 Zed -- "Z" in the phonetic alphabet, now obsolete and replaced by "Zebra"

 ZedRon -- Blimp Squadron (later separated into Blimp-Ron and Blimp-Hedron)

 ZF -- Free balloon

 Z/F -- Zone of Fire (Army)

 ZG -- Canal Zone to Guantanamo (routing designation)

 Z-Hour -- Hour set for attack

 ZK -- Barrage balloon

 ZKN -- Training balloon

 ZKO -- observation balloon

 ZMC -- Experimental metal-clad airship

 ZN -- First two letters in the Navy aircraft designation, indicating an airship (non-rigid)

 ZNH -- Navy airship, air-sea rescue

 ZNJ -- Navy airship, utility

 ZNN -- Non-rigid training airship

 ZNN-G -- Two-engine Navy training and utility airship manufactured by Goodyear

 ZNN-K -- Two-engine Navy training and utility airship manufactured by Goodyear

 ZNN-L -- Two-engine Navy training airship, manufactured by Goodyear

 ZNO -- Non-rigid observation airship

 ZNP -- Non-rigid patrol airship

 ZNP-K -- Two-engine Navy patrol and escort airship manufactured by Goodyear

 ZNP-M -- Two-engine Navy patrol and escort airship manufactured by Goodyear

 ZNS -- Non-rigid scouting airship

 ZofC -- Zones of Communications

 ZofI -- Zone of Interior (Army)

 ZPG -- Airship Group

 ZPRon -- Navy Patrol (lighter-than-air) Squadron

 ZRN -- Rigid training airship

 ZRP -- Rigid patrol airship

 ZRS -- Rigid scouting airship

 ZT -- Zone Time

 ZTO -- Zone Transportation Office (Army)

 ZutRon -- Airship Utility Squadron

Table of Contents
 A  B  C  D  E  F
 G  H  I  J  K  L
 M  N  O  P  Q  R
 S  T  U  V  W  X   Y   Z