2D 2-Dimensional 3D 3-Dimensional

OSME Open Systems Message Exchange

OSP Optical Storage Processor

OSPFIGP Open Shortest-Path First Internal Gateway Protocol [Internet]

OSS Office of Strategic Services (later CIA)

OSS Office Support System

OSS Operation Support System [Telephony, AT&T]

OSSA Office of Space Science and Applications [Space]

OSSE Oriented Scintillation Spectrometer Experiment (on GRO) [Space]

OSTP Office of Science and Technology Policy

OSTP (White House) Office of Science and Technology Policy [US Government]

OT Old Testament

OT OverTime

OTA Office of Technical Assistance

OTA Office of Technology Assessment

OTA Optical Telescope Assembly (on HST) [Space]

OTB Off-Track Betting

OTC Over The Counter (stocks)

OTF Open Token Foundation

OTH-B Over The Horizon - Backscatter (as in radar)

OT&LF Open Taxi & Limousine Foundation

OTR On The Rag

OTS Officers' Training School

OTV Orbital Transfer Vehicle [Space]

OUTWATS OUTward Wide Area Telephone Service [Telephony]

OV Orbital Vehicle [Space]

OV Orbiter Vehicle [Space]

PA Pennsylvania

PA Per Annum

PA Play Aid

PA Power of Attorney

PA Press Agent

PA Private Account

PA Public Address

PA Purchasing Agent

PABX Private Automatic Branch eXchange [Telephony]

PACCOM Pacific Computer Communications network consortium [Networking]

PACX Private Automatic Computer eXchange

PAD Packet Assembler-Disassembler [Networking]

PAH Polycyclic Aromatic Hydrocarbon

PAL Phase Alternation Line-rate

PAL Programmable Array Logic

PAM Payload Assist Module [Space]

PAM Pulse Amplification Modulation

PARC Palo Alto Research Center, xerox

PASS Personal Access Satellite System [NASA]

PATROL Program for Administrative Traffic Reports On Line

PBM Play By Mail game

PBS Public Broadcasting System

PBX Private Branch eXchange [Telephony]

PC Peace Corps

PC PerCent; PerCentage

PC Personal Computer (IBM wants you to believe a specific kind)

PC Player Character (see NPC) [Role-playing]

PC Post Card

PC Post Cibum (after meals)

PC Privileged Character

PC Privy Council

PC Program Counter

PC Progressive Conservative party [Canada]

PC Providence College

PC/AT Personal Computer/Advanced Technology

PCB PolyChlorinated Biphenyl

PCB Printed Circuit Board

PC-DOS Personal Computer DOS

PCI Panel Call Indicator

PCIE President's Council on Integrity and Efficiency

PCL Printer Command Language

PCM Plug-Compatible Mainframe

PCM Pulse Code Modulation

PCPC Personal Computers Peripheral Corporation

PCS Permanent Change of Station

PCTE Portable Common Tools Environment

PCTS Posix Conformance Test Suite

PD Per Diem

PD Police Department

PD Potential Difference

PD Public Domain

PDAD Proposed Draft ADdendum

PDE Partial Differential Equation

PDES Product Data Exchange Specifications

PDF Program Development Facility

PDL Page Description Language

PDL Program Design Language

PDN Public Data Network

PDP Plasma Display Panel

PDP Programmed Data Processor

PDP Programmed Data Processor [DEC]

PDQ Pretty Damned Quick

PDS Premises Distribution System [AT&T]

PDT Pacific Daylight Time

PE Phase Encoded

PE Physical Education

PE Prince Edward island

PE Printer's Error

PE Professional Engineer

PE Protestant Episcopal

PEI Prince Edward Island

PEP Productivity Enhancement Project

PEPE Pepe Est Presque Emacs

PERL Pathologically Eclectic Rubbish Lister

PERL Practical Extraction and Report Language

PEX Phigs/phigs+ Extension to X

PFC Plasma Fusion Center [MIT]

PG Parental Guidance (suggested) [Movie rating]

PGA Professional Graphics Adapter

PGA Pure Grain Alcohol

PHA Pulse Height Analyzer (or Analysis)

PHIGS Programmers Hierarchical Interactive Graphics System

PHS Public Health Service

PhysRev Physical Review Journal - Phys Rev

PI Principal Investigator

PI Priority Interrupt

PI Private Investigator

PIC Plastic/Polyethelene Insulated Cable [Telephony]

PIC Position Independant Code

PIF Paid In Full

PIT Principal, Interest, and Taxes

PIXEL PIcture ELement

PLA Programmable Logic Array

PLATO Programmed Learning for Automated Teaching Operations (U. Ill., early '70s)

PLC Programmable Logic Controller

PLCC Plastic Leaded Chip Carrier

PLL Phase-Locked Loop

PLM Programming Language for Microcomputers

PLO Palestine (sic?) Liberation Organization (?)

PLO Please Leave On

PLSS Portable Life Support System [Space]

PM PayMaster

PM Police Magistrate

PM Post Meridiem

PM Post Meridiem (after noon)

PM PostMaster

PM PostMortem

PM Pressurized Module [Space]

PM Preventive Maintenance

PM Prime Minister

PM Provost Marshal

PMC Permanently Manned Capability [Space]

PMIRR Pressure Modulated InfraRed Radiometer (on Mars Observer) [Space]

PMO Prime Minister's Office

PMOS P channel Metal Oxide Semiconductor (P-MOS) (see MOS)

PMS PreMenstrual Syndrome

PMT PhotoMultiplier Tube

PM/X Presentation Manager for X windows

PN Promissory Note

PNP Positive-Negative-Positive (transistor)

PO Petty Officer

PO Post Office

PO Postal Order

PO Purchase Order

POC Port Of Call

POD Pay On Delivery

POE Port Of Embarkation

POE Port Of Entry

POGO Polar Orbiting Geophysical Observatory

POM Phase Of Moon

POP Point of Presence [Telephony]

POP Post Office Protocol [Networking] (esp. TCP/IP)

POPS Paperless Order Processing System

POR Price On Request

POS Point Of Sale

POS Professional Operating System [DEC]

POSI Promoting conference for OSI

POSIX Portable Operating System for unIX

POSIX Portable Operating System Interface

POTS Plain Old Telephone Service [Telephony]

POTV Personnel Orbit Transfer Vehicle [Space]

POV Point Of View

POW Prisoner Of War

PP Parcel Post

PP Past Participle

PP Post Pay (payphone) [Telephony]

PP Primary Point

PPB Parts Per Billion

PPC Pour Prendre Conge' (to take leave)

PPCS Person to Person, Collect, Special [Telephony]

PPM Parts Per Million

PPN Parameterized Post-Newtonian formalism for general relativity

PPN Project Programmer Number

PPP Point-to-Point Protocol (successor to SLIP (q.v.))

pps Packets per Second

PPS PostPostScriptum

PPT Parts Per Trillion

PPT Pulse Pair Timing

PPT Punched Paper Tape

PQ Province of Quebec

PR PayRoll

PR Public Relations

PR Puerto Rico

PRC Planning Research Corporation

PREPnet Pennsylvania Research & Economic Partnership Network

PRI Primary Rate Interface (ISDN) [Telephony]

PRN pro re nata [Medicine] (as needed?)

PROFS PRofessional OFfice System [IBM]

PROM Programmable Read-Only Memory

PS PicoSecond

PS PostScript

PS PostScriptum

PS Power Steering

PS Power Supply

PS Proposed Standard

PS Public School

PSA Problem Statement Analyzer

PSC Pittsburgh Supercomputer Center

PSC Polar Stratospheric Clouds

PSDN Public Switched Data Network [Telephony]

PSDS Public Switched Digital Service [Telephony, AT&T]

PSE Programming Support Environment

PSF Point Spread Function [Space]

PSG Platoon SerGeant

PSI Performance Systems International [Corporate name, Networking]

PSI Power Systems, Incorporated [Corporate name, Model Railroading]

PSK Phase Shift Keying

PSL Problem Statement Language

PSN Packet Switch Node [ARPANET/MILNET] (replaced IMP)

PSR Product Specific Realizations

PSR PulSaR [Space]

PSS (unknown to me, but something in the UK environment)

PST Pacific Standard Time

PSTN Public Switched Telephone Network

PT Pacific Time

PT Patrol Torpedo (as in PT boat)

PT Physical Therapy

PT Physical Training

PTA Parent-Teacher Association

PTD Parallel Transfer Disk

PTL Praise The Lord (ministry)

PTN Plant Test Number [Telephony] (actual number assigned for 800 service)

PTO Patent and Trademark Office

PTO Please Turn Over

PTO Power Take-Off

PTT Post, Telephone and Telegraph administration

PTV Passenger Transport Vehicle [Space]

PUC Public Utilities Commision

PV Photovoltaic [Space]

PVC Permanent Virtual Circuit (see also VC)

PVC Poly-Vinyl Chloride

PVO Pioneer Venus Orbiter [Space]

PW Prisoner of War (usually POW)

PWG Permanent Working Group

PX Post eXchange (see BX)

QAM Quadrature Amplitude Modulation

QC Quality Control

QC Queen's Counsel (KC when queen reigning)

QD Quaque Die (daily) [Medicine]

QDA Quantity Discount Agreement

QED Quod Erat Demonstrandum (which was to be demonstrated) [Latin]

QEF Quod Erat Faciendum (which was to be done) [Latin]

QEI Quod Erat Inveniendum (which was to be found out) [Latin]

QET Quantum Effect Transistor

QIC Quarter-Inch Cartridge

QID Quater In Die (four times a day) [Medicine]

QLI Query Language Interpreter

QM QuarterMaster

QMC QuarterMaster Corps

QMF Query Management Facility

QMG QuarterMaster General

QMS Quality Micro Systems [Corporate name]

QNS Quantity Not Sufficient

QSO Quasi-Stellar Object [Space]

q.v. ???? (Latin(?): which see)

QWERTY first six keys from left on top alphabetic row of standard keyboard

R Restricted [Movie rating]

R Rolemaster

RA Regular Army

RA Research Assistant

RA Royal Academy

RAAF Royal Australian Air Force

RACE Random Access Card Equipment

RACEP Random Access and Correlation for Extended Performance

RAD Radiation Absorbed Dose

RAD Rapid Access Disk

RADAR RAdio Detection And Ranging

RADM Rear ADMiral

RAF Royal Air Force

RAM Random Access Memory (R/W)

RAM Red Academicia de Mexico (Mexican Academic Network)

RARDE Royal Armaments Research and Development Establishment

RARE R\'eseaux Associ\'es pour la Recherche Europ\'eenne (the European Organization of Research Networks)

RAS Reliability, Availability, and Serviceability

RASC Residence Account Service Center

RATS Radio Amateur Telecommunications Society

R&B Rhythm and Blues (commonly R and B)

RBC Red Blood Count

RBI Runs Batted In

RBOC Regional Bell Operating Company

RC Red Cross

RC Regional Center

RC Resistor-Capacitor circuit (as in filters)

RC Roman Catholic

RCA Radio Corporation of America [Corporate name]

RCAF Royal Canadian Air Force

RCAS Reserve Component Automation System

RCC Radio Common Carrier

RCMP Royal Canadian Mounted Police

RCS Reaction Control System [Space]

R&D Research and Development (commonly R and D)

RD Rural Delivery

RDA Remote Data Access

RDBMS Relational DataBase Management System

RDF Radio Direction Finding

REA Rail Express Agency

RECON Reconnaissance

REM Rapid Eye Movement

REO R. E. Olds

REO Removable, Erasable, Optical

RETMA Radio {something(equipment?)?} {something?} Manufacturers' Association (????)

REXX Restructured EXtended eXecutor

RF Radio Frequency

RF Radio Frequency [Space]

RFC Request For Comments (ala ARPA Internet)

RFD Rehoboth (MA) Fire Department

RFD Rural Free Delivery

RFI Radio Frequency Interference

RFI Radio Frequency Interference [Space]

RFP Request for Proposal

RFQ Request for Quote

RFS Remote File System

RGB Red Green Blue

RGP Raster Graphics Processor

RH Right Hand

RHC Regional (Bell) Holding Company

RHS Right Hand Side

RI Rhode Island

RIACS Research Institute for Advanced Computer Science (NASA)

RIACS Research Institute for Advanced Computer Science [Space]

RIAS Radio In the American Sector, berlin

RIF Reading Is Fundamental

RIF Reduction In Force

RILM Repertoire International de Literature Musicale

RIP Rest In Peace (or Requiescat In Pace : latin)

RIP Routing Interchange Protocol

RIPE R\'eseaux IP Europ\'eenne (European IP Networks) (of RARE, q.v.)

RISC Reduced Instruction Set Computer

RITA Recognition of Information Technology Achievement award

RJE Remote Job Entry

RLC Resistor Inductor Capacitor

RLG Research Libraries Group

RLIN Research Libraries Information Network (run by RLG (q.v.))

RLL Run Length Limited

RMA Radio Manufacturers' Association

RMA Return Materials Authorization

RMATS Remote Maintenance Administration and Traffic System [Telephony]

RMS Remote Manipulator System [Space]

RMS Richard M. Stallman

RMS Root Mean Square

RMS Royal Mail Ship

RN Registered Nurse

RN Royal Navy

RNA RiboNucleic Acid

RNGC Revised New General Catalog [Space]

RNZAF Royal New Zealand Air Force

ROFF Run-OFF

ROG Receipt Of Goods

ROM Range Of Motion [Medicine]

ROM Read-Only Memory

ROM Rupture Of Membrane (as in birth)

ROSAT ROentgen SATellite [Space]

ROSE RATS (q.v.) Open Systems Environment

ROSE Remote Operations Service Entity (per ISO/CCITT layer 7)

ROTC Reserve Officers' Training Corps

ROTS Rotary Out Trunks Selectors

ROYGBIV Red, Orange, Yellow, Green, Blue, Indigo, Violet

RPC Remote Procedure Call

RPG RePort Generator

RPG Role Playing Game

RPI Rensselaer Polytechnic Institute

RPM Revolutions Per Minute

RPN Reverse Polish Notation

RPO Railway Post Office

RPS Revolutions Per Second

RPV Remotely Piloted Vehicle

RQ RuneQuest

RR RailRoad

RR Route Relay

RR Rural Route

RRO Rate and Route Operator [Telephony]

RS Recommended Standard (EIA)

RS Recording Secretary

RS Revised Status

RS Right Side

RS Royal Society

RSCS Remote Spooling Communications Subsystem

RSFSR Russian Soviet Federated Socialist Republic

RSN Real Soon Now

RSU Remote Switching Unit

RSV Revised Standard Edition

RSVP Repondez S'il Vous Plait (please reply)

RSWC Right Side up With Care

RT RadioTelephone

RT RealTime

RTA Remote Trunk Arrangement [Telephony]

RTAC Regional Technical Assistance Center [Telephony]

RTF Rich Text Format

RTFM Read The @!# Manual

RTFM Read The F***ing Manual

RTG Radioisotope Thermoelectric Generator

RTG Radioisotope Thermoelectric Generator [Space]

RTLS Return To Launch Site (Shuttle abort mode) [NASA, Shuttle, Space]

RTR Ready to Run [Model Railroading]

RTR Reel-To-Reel

RTS Request To Send (EIA RS-232-C)

RTTY Radio Teletype

RU Receive Unit

RVD Remote Virtual Disk [MIT]

RW Right Worshipful

RW Right Worthy

RX Receive

Ry Railway

S South

S Supplement

SA Seaman Apprentice

SA Service Assistant

SA Sex Appeal

SA Sine Anno (without date)

SA South Africa

SA South America

SA Subject to Approval

SAA South Atlantic Anomaly

SAA South Atlantic Anomaly [Space]

SAA Systems Application Architecture

SAC Special Area Code [Telephony] (represent services, not places)

SAC Strategic Air Command (see TAC)

SAC Strategic Air Command [US military]

SADD Students Against Drunk Driving

SAFENET Survivable Adaptable Fiberoptic Embedded Network [US Navy]

SAM Surface to Air Missile

SAM Surface-to-Air Missile

SAMA Step-by-step Automatic Message Accounting [Telephony]

SAMPEX Solar Anomalous and Magnetospheric Particle EXplorer [Space]

SAMTO Space And Missile Test Organization [Space]

SAO Smithsonian Astrophysical Observatory [Space]

SAP Second Audio Program

SAP Service Access Point [OSI, Networking]

SAR Search And Rescue

SAR Synthetic Aperture Radar

SARA Satellite pour Astronomie Radio Amateur [Space]

SARA Stichting Academisch Rekencentrum Amsterdam (Amsterdam Universities Computing Center)

SAREX Search and Rescue Exercise [Space]

SAREX Shuttle Amateur Radio Experiment [Space]

SARTS Switched Access Remote Test System

SAS Small Astronomy Satellite

SAS Space Activity Suit [Space]

SASE Self-Addressed Stamped Envelope

SASI Shugart Associates Systems Interface

SAT Satellite [Space]

SAW Surface Acoustic Wave

SBA Small Business Administration

SC Secondary Channel

SC Sectional Center

S&C Skull & Crossbones

SC South Carolina

S/C SpaceCraft [Space]

SC SubCommittee

SCA Shuttle Carrier Aircraft [Space]

SCAD Subsonic Cruise Armed Decoy

SCADC Standard Central Air Data Computer

SCAME SCreen oriented Anti-Misery Editor

SCAMP Single-Chip A-series Mainframe Processor

SCAN Switched Circuit Automatic Network

SCC Specialized Common Carriers

SCC Switching Control Center

SCCS Source Code Control System

SCE Signal Conversion Equipment

SCE Structure Chart Editor

SCI SpaceCraft Incorporated

SCIFI SCIence FIction (often used pejoratively of what really isn't)

SCO Santa Cruz Operation

SCOOPS SCheme Object Oriented Programming System

SCOTS Surveilance and Control Of Transmission Systems

SCSI Small Computer Systems Interface

SCT Schmidt-Cassegrain Telescope [Space]

SCUBA Self Contained Underwater Breathing Apparatus

SCUD Subsonic Cruise Unarmed Decoy

SD South Dakota

SDB Source(?) DeBugger

SDI Standard Disk Interconnect [DEC]

SDI Strategic Defense Initiative [Space, US Government]

SDIO Strategic Defense Initiative Organization [Space, US Government]

SDLC Synchronous Data Link Control [IBM]

SDM Sub-rate Data Multiplexer

SDN Software Defined Network [Telephony, AT&T]

SDN System Development Network (Korea)

SDO Staff Duty Officer

SDSC San Diego Supercomputer Center

SDV Shuttle Derived Vehicle [Space]

SE Service Engineer (see also CE, FE)

SE South East

SEATO SouthEast Asia Treaty Organization

SEC Security Exchange Commission

SECNAV SECretary of the NAVy

SED Stream EDitor

SEI Software Engineering Institute (Carnegie Mellon)

SEI Space Exploration Initiative [Space]

SEL Software Engineering Laboratory

SEM Scanning Electron Microscope

SEST Swedish-European Submillimeter Telescope [Space]

SETI Search for Extra Terrestrial Intelligence [Space]

SETI Search for ExtraTerrestrial Intelligence [Space]

SF San Francisco

SF Science Fiction; Speculative Fiction

SF Standard Form

SF Star Frontiers

SFRPG Science Fiction Role Playing Game

SG StarGuard

SG SubGroup

SGML Standard Generalized Markup Language

SHAPE Supreme Headquarters Allied Powers Europe

SHAR SHell ARchiver

SHCD Sherlock Holmes Consulting Detective

SHF Super High Frequency (3-30GHz)

SHRPG Super Hero Role Playing Game

SI Staten Island

SIAM Society for Industrial and Applied Mathematics

SID Sudden Ionospheric Disturbance [Space]

SIG Special Interest Group

SIGCAT Special Interest Group for Cd-rom Applications Technology

SIMD Single Instruction, Multiple Data

SIMM Single In-line Memory Module

SIMM System Integrated Memory Module

SINE SINE is not EINE

SIPS Satellite Imagery Processing System

SIR Shuttle Imaging Radar [Space]

SIRTF Space (formerly Shuttle) InfraRed Telescope Facility [Space]

SIRTF Space Infrared Telescope Facility [Space]

SIS Strategic Information System

SISCOM Satellite Information System COMpany

SITA Societe Internationale Telecommunications Aeronautiques

SJ Society of Jesus

Skyhook Surface to space "elevator" transportation system [Space]

SL Salvage Loss

SL Space Launch [Space]

SL SpaceLab [Space]

SLA Special Libraries Association

SLA Synchronous Line Adapter

SLAC Stanford Linear Accelerator Center

SLAN Sine Loco, Anno, (vel) Nomine (without place, year, or name)

SLAR Side Looking Airborne Radar

SLAR Side-Looking Airborne Radar [Space]

SLBM Submarine Launched Ballistic Missiles

SLC Space Launch Complex [Space]

SLC Subscriber Loop Carrier [Telephony]

SLDC Synchronous Data Link Control

SLIP Serial Line Internet Protocol

SLIP Serial Line IP (sometimes SL/IP) (see also PPP)

SLP Super Long Play (VHS VCR)

SLS Space(lab) Life Sciences [Space]

SM Service Mark

SMA Sergeant Major of the Army

SMA Spectrum Manufacturers Association

SMC Small Magellanic Cloud (see LMC)

SMC Small Magellanic Cloud [Space]

SMD Storage Module Device (interface standard for disk drives)

SMD Surface Mounted Devices

SMDR Station Message Detail Recording [Telephony]

SMDS Switched Multi-megabit Data Service [Telephony, Networking]

SME Solar Mesosphere Explorer [Space]

SMEGMA Sophisticated Modern Editor with Gloriously Magnificent Abilities

SMERSH Abbr. of Russian phrase meaning "Death to the spies."

SMEX SMall EXplorers [Space]

SMILS Sonobuoy Missile Impact Location System

SMM Solar Maximum Mission (satellite 1980-1989) [Space]

SMTP Simple Mail Transfer Protocol

SMU Southeastern Massachusetts University

SMU Southern Methodist University

SN Science News [Periodical]

SN Serial Number

SN Super Nova

SN SuperNova (e.g., SN1987A) [Space]

SNA Systems Network Architecture [IBM]

SNADS SNA Distribution Services

SNAFU Situation Normal -- All Fouled Up (also more profane versions)

SNAP Shipboard Non-tactical Automated data Processing program

SNAP Sub Network Access Protocol [OSI, Networking]

SNCF Societe National des Chemins de Fer (French National Railways)

SNF Server-Natural Format

SNMP Simple Network Management Protocol [TCP/IP]

SNOBOL StriNg Oriented symbOLic Language

SNPA SubNetwork Point of Attachment

SNR Signal to Noise Ratio

SNR Signal to Noise Ratio [Space]

SNR SuperNova Remnant [Space]

SNU Solar Neutrino Units [Space]

SO Seller's Option

SO Significant Other

SO Space Opera

SO Strike Out

SOAP Symbolic Optimizing Assembler Program

SOFIA Stratospheric Observatory For Infrared Astronomy [Space]