| AU | Aarhus University 
| Others |
| AU | Aberdeen University
| Others |
| AU | Aberystwyth University
| Others |
| AU | About Uncirculated
| Others |
| AU | Absorbance Unit
| Others |
| AU | Absorbance Units
| Others |
| AU | Academic Unit
| Others |
| AU | Access Unit
| Others |
| AU | Adelphi University
| Others |
| AU | Administration Unit
| Others |
| AU | Administrative Units
| Others |
| AU | Aero Union Corporation
| Others |
| AU | African Union
| Others |
| AU | African Unity
| Others |
| AU | Air University
| Others |
| AU | Alcoholics Unanimous
| Others |
| AU | Alfaisal University
| Others |
| AU | Alfred University
| Others |
| AU | Alianza Unidad
| Others |
| AU | Aliens Undercover
| Others |
| AU | Allocation Unit
| Others |
| AU | Almeda University
| Others |
| AU | Alternate Universe
| Others |
| AU | Alternative Universe
| Others |
| AU | American Union
| Others |
| AU | American University
| Others |
| AU | Americans United
| Others |
| AU | Amiga Usenet
| Others |
| AU | Anadolu University
| Others |
| AU | and AU
| Others |
| AU | Anderson University
| Others |
| AU | Andhra University
| Others |
| AU | Andrews University
| Others |
| AU | Anime Universe
| Others |
| AU | Anna University
| Others |
| AU | Annotation Unit
| Others |
| AU | Aperture Unit
| Others |
| AU | Arbitrary Unit
| Others |
| AU | Arbitrary Units
| Others |
| AU | Arellano University
| Others |
| AU | Armageddon Unlimited
| Others |
| AU | Arthur Upfield
| Others |
| AU | Ashford University
| Others |
| AU | Assessment Unit
| Others |
| AU | Assumption University of Thailand
| Others |
| AU | Astronimcal Unit
| Others |
| AU | Astronomical Unit
| Others |
| AU | Astronomical Units
| Others |
| AU | Athabasca University
| Others |
| AU | Athletic Union
| Others |
| AU | Atomic Units
| Others |
| AU | Auburn University
| Others |
| AU | Auburn Univirsity
| Others |
| au | Audio
| Others |
| AU | Audio Unit
| Others |
| AU | Audio Units
| Others |
| AU | Auris Utraque (both ears)
| Others |
| AU | Aurora University
| Others |
| AU | Australia
| Others |
| AU | Authenticated User
| Others |
| AU | Authenticity Augmentative
| Others |
| AU | Author
| Others |
| AU | Authorized User
| Others |
| AU | Auto Union
| Others |
| AU | Autodesk University
| Others |
| AU | Automatic Update
| Others |
| AU | Automatic Updates
| Others |
| AU | Automotive Use
| Others |
| AU | Avengers University
| Others |
| AU | Awfully Underwhelming
| Others |
| AU | Awkward University
| Others |
| AU | Gold
| Element |
| AU | Sound - basic 8-bit compressed audio file
| Others |