Underneath the umbrella term of AUO, there are four categories that I know of at this point:
AWO (formerly called AUO), Advanced Wire Order, is what @Blackhole927 discovered long ago.
ABO, or Advanced Block Order, is having two blocks run at the same time, and depending on which one was made first, creating different actions based off of what order the blocks were made in.
ACO, or Advanced Channel Order, is having two diffrent channels run at the same time, and depending on their relative ages, different effects can happen.
And finally, the weird recluse of the family:
AMO, or Advanced Mixed Order, would be creating a block and wire that should run at the same time, and depending on which one was made first, will produce different results. If you want greater detail, go to @Blackhole927 's Advanced Update Order | Difficulty: to learn more.
Hope this helps, for people who don’t understand ABO.