What does AOP stand for?

Abnormal Operating Procedure (NRCH)

Academy of Orthomolecular Psychiatry - Later, AOM (EA)

Accuracy of Position (MCD)

Acetoxypregnenolone - Pharmacology

Acidity Oxidation Potential - Chemistry

Acrylic Optics Corp. (SAUO)

Additive Operational Project - Army (MCD)

Address Out-Port (TIMI)

Adiposity-Oligomenorrheaparotid Swelling - Syndrome - Medicine (MELL)

Administrative and Operational Procedure (MCD)

Advanced On-Board Processor - Computer

Advanced Oxidation Process - Chemistry

Aerial Observation Post (SAUO)

Aerodrome Operation (DA)

Aero Dymanics Inc., Lodi, CA - Manufacturer code for watercraft hull identification number (USCG)

Aeropiloto-Sociedade Exploradora de Servicos Aereos Lda. - Portugal - ICAO designator (FAAC)

Aerospace Observation Platform

Airborne Observation Post (SAUO)

Airborne Optical Platform

Aircraft Out for Parts (MCD)

Airline Operations Planning Model (SAUS)

Air Observation Plane (SAUS)

Air Observation Post

Airport Overlay District (SAUO)

Allied Ordnance Publications (NATG)

All Other Perils - Insurance

All Over Pattern - Quilting

Altoona Area Public Library, Altoona, PA - OCLC symbol (OCLC)

American Journal of Optometry and Physiological Optics - A publication (SAUS)

American Order of Pioneers (GEAB)

Amino-Oligopeptidase - An enzyme

Ammonia Oxidation Plant (MCD)

Annual Operating Plan (VLIE)

Annual Operating Program - Army

Anodal Opening Picture - Physiology

Anomalistic Observational Phenomena - In study of UFO's

Any One Person - Insurance (AIA)

Aortic-Pressure Pulse (SAUS)

Apnea of Prematurity - Also, AOI (Apnea of Infancy) (PAZ)

Applicant Outreach Program - Department of Labor

Apprenticeship Outreach Program - Bureau of Apprenticeship and Training (OICC)

Approved Operating Program - Military technology (DDF)

Arab Organization of Petroleum Exporting Countries (SAUS)

Arctic Offshore Program - National Science Foundation (GFGA)

Area of Probability (NVT)

Area of Projection (SAUS)

Arithmetic Operation (VLIE)

Armoured Observation Post - British and Canadian - World War II

Army Observation Plane (SAUS)

Army Observation Post - British military (DMA)

Army Order of Precedence - Military technology (DDF)

Artillery Observation Post - British military (DMA)

Assembly and Operations Plan

Associated Organizations for Professionals in Education (SAUS)

Association of Oil Pipe Lines (SAUO)

Association of Online Professionals

Association of Optical Practitioners - British (BI)

Association of Optometrists - British (DBA)

Association of Organisers of Physical Education (SAUO)

Association of Organisers of Physical Education, Scotland (SAUS)

Association of Osteopathic Publications - Defunct

Association of Photographers (SAUO)

Astrophysical Observatory, Potsdam (SAUS)

Atomic Ordnance Platoon (NG)

Australia. Commonwealth Scientific and Industrial Research Organisation. Division of Plant Industry. Annual Report - A publication (SAUS)

Automatic Operations Panel

Environmental Protection Agency Analytical Operations Branch

Rock Springs, WY - Location identifier - FAA (FAAL)