| * | Born | |
| + | Died | |
| A | Acre | |
| AAGRA | Australasian Association of Genealogists and Record Agents | |
| AAS | Anno Aetatis Suae (Died in the year of (his/her) age) | |
| AAS | American Antiquarian Society | |
| ACC | ACCording to …. | |
| ACKD | Acknowledged | |
| ADMR | Administrator | |
| ADMX | Administratrix | |
| ADS | AD Sectam (at the suit of ….) | |
| AET | Aetatis (about the age of ….) | |
| AFN | Ancestral File Number | |
| AG | Accredited Genealogist | |
| AG:ABC | American Genealogy: A Basic Course | |
| AGRA | Association of Genealogists and Record Agents | |
| AH | Aunts Husband | |
| AIHA | Australian-Irish Heritage Association | |
| ALD | ALDerman | |
| AM | Anno Mundi (year of the world) | |
| AMHS | Alberta Métis Historical Society | |
| APG | Association of Professional Genealogists | |
| APGI | Association of Professional Genealogists in Ireland | |
| APGQ | Association of Professional Genealogists Quarterly | |
| API | Asian / Pacific Islander | |
