AU
AU is most often seen as the country code for Australia, but it also appears in academic writing to denote an author and in tech settings for automatic updates or atomic units.
Medical
Miscellaneous
Armageddon Unlimited
Aliens Undercover
Anime Universe
Arbitrary Units
Absorbance Units
Atomic Units
Alternate Universe
Astronomical Units
Awfully Underwhelming
Allocation Unit
Aperture Unit
and AU
Alcoholics Unanimous
About Uncirculated
Community
Governmental
Academic & Science
Author
Alfred University
Almeda University
Adelphi University
Assumption University of Thailand
Anadolu University
Andhra University
Auburn Univirsity
Absorbance Unit
Arbitrary Unit
Air University
Anna University
Anderson University
Athabasca University
Autodesk University
American University
Auburn University
Andrews University
Aarhus University
Regional
Computing
Authorized User
Audio Units
Automatic Updates
Authenticated User
Automatic Update
Amiga Usenet
Access Unit
basic 8-bit compressed audio file
Audio Unit