What does PRO stand for? 

Boeing Procedure

Miscellaneous » Aircraft & Aviation

DOS graphics PROfile file

Computing » File Extensions

Ford Probe

Miscellaneous » Automotive

In Favor Of

Governmental » US Government -- and more...

Paddock Radical Options

Governmental » Law & Legal

Patient Reported Outcome

Medical » Hospitals

Patient Reported Outcomes

Miscellaneous » Unclassified

Patient-Reported Outcome

Medical » British Medicine

Patients’ Rights Organization

Medical » Hospitals

Peer Review Organisation

Medical » British Medicine

Peer Review Organization

Business » General Business

Peer Review Organizations

Miscellaneous » Unclassified

Peer-Review Organization

Medical » Laboratory

Peking Ragnarok Online

Computing » Gaming

People Relating to Others

Community » Educational

People, Resources, and Organizations

Business » General Business

Perfectly Respectful Obedience

Governmental » Military

Performance Reliability Opportunity

Miscellaneous » Unclassified

Performance Reward Options

Business » Occupation & Positions

Performance Rights Organization

Community » Performing Arts

Personnel Recovery Officer

Governmental » Military

Personnel Relations Officer

Miscellaneous » Working Groups

Philippine Ragnarok Online

Internet

Phillipines Ragnarok Online

Internet » Websites

Photographic Research Organization

Business » Companies & Firms

Physician Review Organization

Medical » Hospitals

Pittsburgh Relies On

Community

Pittsburgh Roleplaying Organization

Computing » Gaming

Player Referee Organization

Sports

Player Run Organization

Sports

Portable Remote Object

Computing » IT

Positive Recreation Opportunities

Community

Practical Regional Opportunity

Business » International Business

Pray Review Organize

Community » Religion

Precision Residue Opener

Academic & Science » Physics

Predicament, Response, and Outcome

Governmental » Law & Legal

Predictable Research Online

Internet

Pride, Respect, and Opportunity

Governmental » Law & Legal

Priority Repair Order

Governmental » Military

Privilege, Responsibility, and Opportunity

Business » Occupation & Positions

Probing Rectal Orifices

Miscellaneous » Funnies

Procedure

Miscellaneous » Manufacturing

PROceed

Governmental » NASA

Producer Responsibility Organization

Business » Trade Associations -- and more...

Professional

Business » Occupation & Positions -- and more...

PROfessional (for licensed professionals only)

Internet » Domain Names

Professional Edition

Miscellaneous » Automotive

Professional Racers Organization

Miscellaneous » Automotive

Professional Recreation Organization

Community » Parks & Recreation

Professional Referee Organization

Miscellaneous » Unclassified

Professional Rental Owner

Business » Occupation & Positions

Professional Restylers Organization

Miscellaneous » Automotive

Professional Review Organisation

Medical » British Medicine

Professional Rugby Organization

Sports » Rugby

Profile Configuration Data

Computing » File Extensions

proflavin

Medical » British Medicine

PROgesterone

Medical » Physiology

Progressive Dig

Business » London Stock Exchange

Progressive Re-integration Opportunity

Governmental » Law & Legal

Progressive Rotating Order

Miscellaneous » Unclassified

proline

Medical » British Medicine

Prolog File

Computing » IT

Prolog language source code file

Computing » File Extensions

prolyl

Medical » British Medicine

Prominent

Governmental » Police

Pronation

Medical » Surgical

Proper Ram-air Orientation

Governmental » Military

Prophecy International Holdings, LTD.

Business » ASX Symbols

Prophylactic

Medical » Physiology

propranolol

Medical » British Medicine

Propulsion

Miscellaneous » Automotive

Protecting the Right to Organize

Miscellaneous » Unclassified

Protections of Rights of Others

Computing » IT

PROtein

Medical » Human Genome

Provencal, Old (to 1500)

Regional » Language Codes (3 Letters)

Proverbs

Community » Bible

Public Record Office

Governmental » State & Local -- and more...

Public Record Office (UK Government)

Governmental

Public Records Office

Governmental

Public Relations Office

Business » General Business

Public Relations Officer

Miscellaneous » Toastmasters -- and more...

Public Research Organization

Community » Non-Profit Organizations

Pumpability Reference Oil

Miscellaneous » Automotive

Punk Rock Orchestra

Community » Music