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 (Telefonia)
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 (Espacial)
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 (Telefonia)
PC Peace Corps
PC PerCent; PerCentage
PC Personal Computer
PC Player Character (veja também NPC) [Role-playing]
PC Post Card
PC Post Cibum (after meals)
PC Privileged Character
PC Privy Council
PC Program Counter
PC Progressive Conservative party (Canadá)
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 (filme de ação)
PGA Professional Graphics Adapter
PGA Pure Grain Alcohol
PHA Pulse Height Analyzer (ou Análise)
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 (Telefonia)
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 
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 (Espacial)
PM PayMaster
PM Police Magistrate
PM Post Meridiem
PM Post Meridiem (depois da meia-noite)
PM PostMaster
PM PostMortem
PM Pressurized Module (Espacial)
PM Preventive Maintenance
PM Prime Minister
PM Provost Marshal
PMC Permanently Manned Capability (Espacial)
PMIRR Pressure Modulated InfraRed Radiometer (em Observador de Marte) (Espacial)
PMO Prime Minister's Office
PMOS P channel Metal Oxide Semiconductor (P-MOS) (veja também 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 (Telefonia)
POP Post Office Protocol (Networking) (especialmente 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 (Telefonia)
POTV Personnel Orbit Transfer Vehicle (Espacial)
POV Point Of View
POW Prisoner Of War
PP Parcel Post
PP Past Participle
PP Post Pay (payphone) (Telefonia)
PP Primary Point
PPB Parts Per Billion
PPC Pour Prendre Conge' 
PPCS Person to Person, Collect, Special (Telefonia)
PPM Parts Per Million
PPN Parameterized Post-Newtonian formalism for general relativity
PPN Project Programmer Number
PPP Point-to-Point Protocol (sucessor para 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) (Telefonia)
PRN pro re nata (Medicina) 
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 (Telefonia)
PSDS Public Switched Digital Service [Telefonia, AT&T]
PSE Programming Support Environment
PSF Point Spread Function (Espacial)
PSG Platoon SerGeant
PSI Performance Systems International [Nome de companhia, Networking]
PSI Power Systems, Incorporated [Nome de companhia]
PSK Phase Shift Keying
PSL Problem Statement Language
PSN Packet Switch Node [ARPANET/MILNET] (substituído IMP)
PSR Product Specific Realizations
PSR PulSaR (Espacial)
PSS (não conhecido para mim)
PST Pacific Standard Time
PSTN Public Switched Telephone Network
PT Pacific Time
PT Patrol Torpedo 
PT Physical Therapy
PT Physical Training
PTA Parent-Teacher Association
PTD Parallel Transfer Disk
PTL Praise The Lord (Ministerial)
PTN Plant Test Number (Telefonia) 
PTO Patent and Trademark Office 
PTO Please Turn Over 
PTO Power Take-Off
PTT Post, Telephone and Telegraph administration
PTV Passenger Transport Vehicle (Espacial)
PUC Public Utilities Commision
PUC Pontifícia University Católic
PV Photovoltaic (Espacial)
PVC Permanent Virtual Circuit (veja também VC)
PVC Poly-Vinyl Chloride
PVO Pioneer Venus Orbiter (Espacial)
PW Prisoner of War (usualmente POW)
PWG Permanent Working Group
PX Post eXchange (veja também BX)
® Pesquisa RXA