What does P.O. stand for?

What does P.O. mean?

PO	Path Order Academic & Science » Mathematics
PO	Prodos Order Miscellaneous » Science Fiction
PO	Per Os (by mouth) Medical » Physiology
PO	Piconics Governmental » Suppliers
PO	Political Outlines Governmental » US Government
PO	A Purchasing Order Miscellaneous » Unclassified
PO	Partition Organized Computing » Networking
PO	Provocative Operations Miscellaneous » Unclassified
PO	Pilot Officer (Royal Air Force) Governmental » Military
PO	Per Os (Latin: by mouth, orally) International » Latin
PO	Parameters For Optimization Miscellaneous » Unclassified
PO	Printer Operators Miscellaneous » Unclassified
PO	Polyteknikkojen Orkesteri Miscellaneous » Unclassified
PO	Proforma Order Community » Law
PO	Placeable Object Computing » Databases
PO	Particular Orifice Miscellaneous » Unclassified
PO	Prosody Only Miscellaneous » Unclassified
PO	Pamatnik Odboje Business » Firms
PO	Prodigal Outcasts Miscellaneous » Unclassified
PO	Pee-Ons Business » Positions
PO	Prato (Provence) International » Italian
PO	Protable Object Miscellaneous » Unclassified
PO	Per Os (By Mouth, or Orally) Medical » Hospitals
PO	Portable Obejects Miscellaneous » Unclassified
PO	Police Officer Business » Positions

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