What does P.O. stand for?

What does P.O. mean?

PO	Primary Outputs Miscellaneous » Unclassified
PO	Purple Onion Miscellaneous » Unclassified
PO	Painting Operations Miscellaneous » Unclassified
PO	Peoples Organization Miscellaneous » Unclassified
PO	Planning Objective Business » General
PO	Pooped Out Internet » Chat
PO	People's Organization Miscellaneous » Unclassified
PO	Physicians Orders Medical » Physiology
PO	Program Owner Computing » Software
PO	Provocative Operation Governmental » Military
PO	Printer Operator Business » Positions
PO	Posting Online Internet » Chat
PO	Passenger Operation Governmental » Transportation
PO	Partial Open Academic & Science » Electronics
PO	Pareto Optimal Academic & Science » Mathematics
PO	Presenting Officer Business » Positions
PO	Project Originals Miscellaneous » Construction
PO	Promotion Opportunity Business » Positions
PO	Persistent Offender Governmental » Police
PO	Private Offer Business » General
PO	Personal Offer Business » Positions
PO	Parity Outer Computing » Software
PO	Pants Optional Miscellaneous » Clothes
PO	Paint Operation Business » Products
PO	Path Ordered Miscellaneous » Unclassified

Po(n.): a river in Italy, flowing E from the Alps in the NW to the Adriatic. 418 mi. (669 km) long.