| A3 | Anytime, anywhere, anyplace |
| AAF | As a friend |
| AAF | As a matter of fact |
| AAK | Asleep at keyboard |
| AAMOF | As a matter of fact |
| AAP | Always a pleasure |
| AAR | At any rate |
| AAS | Alive and smiling |
| ABC | Already been chewed |
| ABT | About |
| ABT2 | About to |
| ADBB | All done, bye-bye |
| ADD | Address |
| ADDY | Address |
| ADIP | Another day in paradise |
| ADN | Any day now |
| AEAP | As early as possible |
| AFAIK | As far as I know |
| AFK | Away from keyboard |
| AH | At home |
| AIGHT | Alright |
| AIR | As I remember |
| AISI | As I see it |
| AKA | Also known as |
| ALCON | All concerned |
| ALOL | Actually laughing out loud |
| AMAP | As much as possible |
| AML | All my love |