AC

"AC" can mean Ace Combat.
Ace combat 3 (the first wich had the Name *Ace* Combat) would be called "AC3"
AC04 (do not type AC4) is Ace Combat 04
AC5 is Ace Combat 5
ACZ, AC0 or AC Zero means Ace Combat Zero
AC6 is Ace Combat 6
ACAH is Ace Combat Assault Horizon
AC7 is Ace Combat 7

Me: I like ACAH and AC6
65% of the Ace Combat Community: Are you Stupid ACAH and AC6 are the worst games in the whole series!!!