[address] See: [PUBLIC-ADDRESS SYSTEM].

[Adminisphere] The rarified organizational layers above the rank and file that […]

[advance] See: [IN ADVANCE] or [IN ADVANCE OF].

[advantage] See: [TAKE ADVANTAGE OF], [TO ADVANTAGE].

[AFAIC] "as far as I'm concerned", or "as far as I […]

[AFAICS] "as far as I can see"

[AFAICT] "as far as I can tell"

[AFAIK] "as far as I know"

[AFAIR] "as far as I recall", or "as far as I […]

[AFC, AFK] "away from computer/keyboard"