What does an stand for?

Above Named (ADWA)

Anatomic - Anatomy (DAVI)

Andorra - MARC country of publication code - Library of Congress (LCCP)

Aneurysm - Medicine (EDAA)

Animate - Linguistics (IEL)

Anisoyl - As substituent on nucleoside - Biochemistry

Anorthite - CIPW classification - Geology

Ante - Before - Latin

Arrival Notice (EBF)

East China Sea and Area - MARC geographic area code - Library of Congress (LCCP)

Normal Atmosphere (DAVI)

Abbott's New Cases - New York - A publication (DLA)

Abducent Nerve - Medicine (MELL)

Above-Named

Abr-Nahrain (BJA)

Absolute Name (SAUS)

Abstract Number - Database terminology (NITA)

Acanthosis Nigricans - Medicine

Accession Number - Online database field identifier

Access Node (VERA)

Accessory Nerve - Medicine (MELL)

Accion Nacional - National Action - Spain - Political party (PPE)

Account Number

Acetonitrile - Organic chemistry

Acide Nucleique - French - Medicine

Acid Number - Chemistry

Acne Neonatorum - Medicine (DMAA)

Acoustic Neuroma - Medicine (DMAA)

Acrylonitrile - Organic chemistry

Acrylonitrile Group (EA)

Action Nationale - National Action for People and Homeland - Switzerland - Political party (PPE)

Active Network (ELAL)

Acuerdo Nacional - Paraguay - Political party (EY)

Acute Nephritis - Medicine (MELL)

Added Name - Travel industry (TRID)

Administrative Note

Adult Normal - Medicine (DMAA)

Advanced Navigator - Air Force

Advice Note (ADA)

Aerodynamics Note

Afferent Nerve - Medicine (MELL)

Africa Network - An association (EA)

Africa News - A publication

African Network (SAUO)

African Notes - Ibadan - A publication

Agencia Nacional - National Agency - Press agency - Brazil

Agency Name - Database terminology (NITA)

Aircraft Number (SAUS)

Air Force-Navy (SAUO)

Airmail Notice (SAUS)

Airman - Nonrated enlisted man - Navy

Air Navigation

Air Nicaragua (SAUO)

Air Reduction (SAUS)

Alaska Network (SAUS)

Algeria - NCIC country-territory code (NCIC)

Alianza Nacional - National Alliance - Spain - Political party (PPE)

Alleanza Nationale (Italy) - Political party (PSAP)

All Normal - Hematology

Alphameric (SAUS)

Alphanumeric

Alterations Notice (ACAE)

Alternating Network (SAUS)

Ambient Noise - Composite of sounds present at a given spot in the ocean (NVT)

Ambulances for Nicaragua (EA)

American Navy (SAUO)

American Newspapers, 1821-1936 - A bibliographic publication

Ammonium Nitrate - Inorganic chemistry

Amoco Corp. - NYSE symbol

Amplifier Noise (ELAL)

Amplitude Noise (ELAL)

Amyl Nitrite - Medicine (MELL)

Andorra - GeoNet country code (GEON)

Andorra - Federal Information Processing Standard (FIPS) country code (GEON)

Androgyne (DHP)

Anemone - Botany

Anesthesia - or Anesthetic - Medicine (DAVI)

Anesthesiology - Medical specialty (DHSM)

Aneurysm

Anglo-Norman - Language, etc.

Anhydrous

Animal

Animate (WGA)

Anisometropia - Ophthalmology

Annex

Anno - or Annus - Year - Latin

Anode

Anonymous (WGA)

Anorexia Nervosa - Medicine

Ansbach - German license plate city code

Ansett Airlines of Australia - ICAO designator (AD)

Answer

Answering Flag - Navy - British

Antenatal - Medicine

Anterior - Medicine (EDAA)

Anther - Botany

Antineuraminidase (DB)

Antinode (SAUS)

Antonov - Former USSR - ICAO aircraft manufacturer identifier (ICAO)

Anxiety Neurosis - Medicine (MELL)

Apalachicola Northern Railroad Co. - AAR code

Appeals Notes - A publication (DLA)

Applications Notice (SAUS)

Archdeacon Nares - Pseudonym used by Robert Nares

Arctic Network - Association (EA)

Arcuate Nucleus - In the medulla oblongata

Argentaffin - Cytology

Arithmetic Notation (SAUS)

Army and Navy

Army-Navy Joint Type Ordnance

Army Number (SAUS)

Army Nurse - Military technology (DDF)

Arrival Notice - Shipping

Ascending Neuron - Neurology

Aseptic Necrosis - Medicine

Aspergillus niger - Factor

Assignee Name - Database terminology (NITA)

Associated Number (SAUS)

Associate in Nursing

Astronautics Notice (AAG)

Astronavigation (NATG)

Ataxic Nystagmus - Medicine (MELL)

Atomic Number

Attributable Number (MELL)

Austronesian - Linguistics (IEL)

Author's Note

Autograph Note (BARN)

Autonation - Company symbol

AutoNation, Inc. - NYSE symbol (SPSG)

Autonetics (KSC)

Autonomic Neuropathy - Medicine (MELL)

Avascular Necrosis - Medicine (AAMN)

Axillary Node - Medicine (MELL)

Axle Nut (DICI)

Axonal Neuropathy - Medicine (MELL)

Die Akkadische Namengebung - A publication (BJA)

National Agreement - Paraguay (PD)

National Alliance - Italy - Political party

Neerlandia Public Library, Alberta - Library symbol - National Library of Canada (NLC)

Netherlands Antilles - ANSI two-letter standard code (CNC)

Net Laying Ship - Later, ANL - Navy symbol

Rhone-Poulenc - France - Research code symbol

Actinon (MAE)

Aktinon (SAUS)

Anabasis - of Xenophon - Classical studies (OCD)

Anaesthetic

Andreas Bonellus de Barulo - Flourished, 1260-71 - Authority cited in pre-1607 legal work (DSA)

Andreas de Capua - Flourished, 1242-57 - Authority cited in pre-1607 legal work (DSA)

Andria - of Terence - Classical studies (OCD)

Angelus de Ubaldis - Deceased, 1407 - Authority cited in pre-1607 legal work (DSA)

Anisometropia

Annals (DIAR)

Annamese (SAUS)

Anode

Anonymous Reports at End of Benloe - 1661 - England - A publication (DLA)

Antigen

Antonius de Butrio - Deceased, 1408 - Authority cited in pre-1607 legal work (DSA)

Atmosphere, Normal (MAE)