ACIS
American Committee for Interoperable Systems
TACIS
Technical Assistance to the Commonwealth of Independent States - Technische Hilfe zugunsten der Neuen Unabhängigen Staaten der ehemaligen Sowjetunion und der Mongolei
A-SIT
Austrian Security Information Technology center
AA
American national standard code for information interchange (ASCII) Art
AARNET
Australian Academic Research NETwork
AASP
American national standard code for information interchange (ASCII) Asynchronous Support Package
ABTS
American standard code for information interchange (ASCII) Block Terminal Services