| Abkürzung | Bereich | Staat | Bedeutung |
| A | Staat | Austria (Österreich) | |
| Physik | Bruchdehnung | ||
| Fläche | |||
| a | Physik | Beschleunigung | |
| AA | Computer | Auto Answer | |
| AAP | Computer | Auto Access Point | |
| ABEND | Computer | Abnormal End | |
| ADV | Technik | D | Automatische Datenverarbeitung |
| ABI | Computer | Application Binary Interface | |
| ABIOS | Computer | Advanced BIOS | |
| Abk. | Allgemein | D | Abkürzung |
| ABT | Computer | Abort | |
| AC | Technik | Accumulator | |
| Accu | Technik | D | Accumulator |
| ACL | Computer | Access Control List | |
| ACS | Computer | Access Control System | |
| Asynchronous Communication Server | |||
| ACU | Computer | Automatic Calling Unit | |
| ADC | Computer | Analog to Digital Converter | |
| ADI | Software | Autocad Device Interface | |
| ADMD | Computer | Administrative Management Domain | |
| ADS | Technik | Automatic Distribution System | |
| Computer | Application Development Solutions | ||
| Application Development System | |||
| ADSC | Computer | Address Status Changed (Status der Adresse geändert) | |
| ADU | Technik | Automatic Dialing Unit (Automatik-Wahl-Einheit) | |
| AEB | Computer | Analog Expansion Bus | |
| AGA | Computer | Advanced Graphics Adapter | |
| AI | Technik | Analog Input (Analoger Eingang) | |
| Computer | Artificial Intelligence | ||
| allg. | Allgemein | D | allgemein |
| ALGOL | Computer | Algorithmic Language (Programmiersprache) | |
| AM | Technik | Amplitude Modulation | |
| ANSI | Institut | USA | American National Standards Institute |
| Normung | |||
| AO | Technik | Analog Output (Analoger Ausgang) | |
| APA | Verband | USA | Amateur Press Association |
| API | Computer | Applications Programming Interface | |
| APL | Computer | Algorithmic Procedural Language (Programmiersprache) | |
| APM | Technik | Advanced Power Management | |
| App. | Haus | D | Appartment |
| Arc | Mathematik | Arcus | |
| ARCA | Computer | Advanced Risc Computing Architecture | |
| ARQ | Computer | Automatic Repeat Request | |
| ARU | Technik | Audio Response Unit | |
| ASA | Institut | USA | Amercian Standards Association |
| Normung | |||
| ASAP | Technik | Automatic Switching And Processing | |
| ASCII | Software | American Standard Code for Information Interchange | |
| ASIT | Technik | Advanced Security and Identification Technology | |
| ASP | Computer | Advanced Signal Processor | |
| Verband | USA | Association of Shareware Professionals | |
| ASPI | Software | Advanced SCSI Programming Interface | |
| ASPS | Computer | Advanced Signal Processing System | |
| ASYNC | Technik | Asynchron | |
| AT | Technik | Advanced Technology | |
| AT&T | Gesellschaft | USA | American Telegraph and Telephone Company |
| ATA | Computer | AT Bus Attachment | |
| ATC | Computer | Address Translation Cache | |
| ATDP | Technik | Attention Dial Pulse | |
| ATDT | Technik | Attention Dial Tone | |
| ATF | Technik | Automatic Track Finding | |
| ATH | Technik | Attention Hang-up | |
| ATM | Technik | Asynchroner Transfer Modus | |
| ATP | Software | Appletalk Transaction Protocol | |
| Auto | Technik | Automatik | |
| Technik | D | Automobile | |
| AVON | Allgemein | D | Amtliches Verzeichniß der Orts-Netz-Kennzahlen |
| AWI | Institut | D | Alfred Wegener Institut |
| AWL | Wirtschaft | D | Anweisungsliste |