What does PSO stand for?

Pad Safety Officer - Aerospace (MCD)

Paint Spray Outfit

Pasadena Symphony Orchestra (SAUS)

Paseo

Pasto - Colombia - Airport symbol (OAG)

Pasto - Colombia - Seismograph station code, US Geological Survey (SEIS)

Pauli Spin Operator - Physics

Peace Support Operation - Military technology (DDF)

Peacetime Stockage Objective - DoD (AFIT)

Pearson plc ADR - NYSE symbol

Pending Service Order (SAUS)

Penobscot Shoe - AMEX symbol

Penobscot Shoe Co. - AMEX symbol (SPSG)

Personal Staff Officer - Australia

Personnel Security Officer - Military

Personnel Selection Officer - British military (DMA)

Personnel Services Organisation - Australia

Phantasy Star Online

Phoenix Symphony Orchestra (SAUS)

Phorate Sulfoxide (SAUS)

Piano-Shaped Object

Pilot Systems Officer (SAUS)

Pilot Systems Operator

Pittsburgh Symphony Orchestra (SAUS)

Planet Sensor Output

Point Surface Origin

Polaris Systems Officer - British military (DMA)

Policy Studies Organization (EA)

Polish Sign Language - Language code (ETLW)

Political Survey Officer (SAUS)

Political Survey Officers - Navy

Polysulfon (SAUS)

Polysulfone - Also, PS - Organic chemistry

Portland Symphony Orchestra (SAUS)

Port Services Office - or Officer (DNAB)

Prague Symphony Orchestra (SAUS)

Primary Standardization Office - Military (AABC)

Principal Scientific Officer - British

Principal Staff Officer - British military (DMA)

Procurement Services Office

Product Superior to Operator (TONE)

Product Support Organization

Profco Resources Ltd. - Vancouver Stock Exchange symbol

Professional Services Organization (GART)

Programmable Storage Oscilloscope (CIST)

Program Secretarial Officer (COE)

Program Senior Official (COE)

Program Staff Officer

Progressive Supranuclear Ophthalmoplegia (CPH)

Project Science Office (EOSA)

Prospective Supply Officer (DNAB)

Protective Security Officer

Protective Service Operations (SAUS)

Protocol Supporting Organisation (ALPHA)

Protocol Supporting Organization (SAUS)

Provider Sponsored Organization

Provisions Supply Office - Military

Proximal Subungual Onychomycosis

Psychiatric Services Officer - Australia

Publications Supply Officer - Military

Publicity Security Officer - Navy

Public Safety Officer

Public Service Obligation - Australia

Public Service Organisation - Government grant - British