| Parties to the Nauru Agreement | Academic & Science |
| Protein Nucleic Acid | Academic & Science |
| Principles of Naval Architecture | Academic & Science |
| Philippine Neurological Association | Academic & Science |
| Pacific Northern Academy | Academic & Science |
| Possessive Noun Adjective | Academic & Science |
| Professional National Accountant (australia) | Accounts and Finance |
| Pamplona | Airport Code |
| Pacific Northwest Associates, LLC | Business |
| Philippine Nurses Association | Business |
| Penna Consulting, P.L.C. | Business |
| Pan Australian Resources Ltd | Business |
| P-nitro-anilide | Chemistry |
| Positive/negative Anomaly | Chemistry |
| Patronato Nacional Antituberculoso | Community |
| Palestine News Agency | Community |
| Progressive Network Academy | Community |
| Pituitary Network Association | Community |
| Philippines News Agency | Community |
| Phinney Neighborhood Associations | Community |
| Pacific Northwest Association | Community |
| Pennsylvania NewsMedia Association | Community |
| Pennsylvania Newspaper Association | Community |
| Philippine News Agency | Community |
| Phinney Neighborhood Association | Community |
| Personal Navigation Assistant | Computer Hardware |
| Peripheral Narrative Analysis | Computing |
| Phoneline Network Adapter | Computing |
| Portable Network Audio | Computing |
| Portable Network Analyzer | Computing |
| Probability Networks and Algorithms | Computing |
| Progressive Networks Audio | Computing |
| Programmable Network Access | Computing |
| Program Neighborhood Agent | Computing |
| Private Network Adapter | Computing |
| Pacific North American | Earth Science |
| Paraffins Naphthenes Aromatics | General |
| Peptide Nucleic Acids | General |
| Parts Not Available | General |
| Pulmonary Nodular Amyloidosis | General |
| PNA Network Analyzer | General |
| Physical Needs Assessment | General |
| Pages Needing Attention | General |
| Paraffins Naphthenes and Aromatics | General |
| Porsche North America | General |
| Puria Nafisi Azizi | General |
| Professional Network on Aging | General |
| Preferred Network Access | General |
| Professor Nijssen Associates | General |
| Primes Non Acquises | General |
| Photo Nightscape Awards | General |
| Podiatrist Needs Alcohol | General |
| Parties to Nauru Agreement | General |
| Network Analyzers | General |
| Prevention Needs Assessment | General |
| Performance Network Analyzer | General |
| Pakistan National Alliance | Governmental |
| Palestine National Authority | Governmental |
| Polish National Alliance | Governmental |
| Palestinian National Authority | Governmental |
| Phoneline Networking Alliance | Governmental |
| Policia Nacional de Angola | International |
| Progressive Neuronal Abiotrophy | Medical |
| Peptide Nucleic Acid | Medical |
| Post-Natal Age | Medical |
| Paris Nomina Anatomica | Medical |
| Partial Nail Avulsion | Medical |
| Percutaneous Needle Aspiration | Medical |
| Personal Needs Allowance | Medical |
| Pharmaceutical Needs Assessment | Medical |
| Purine Nucleoside Analogue | Medical |
| Psychiatric Nurses Association | Medical |
| Physician Network Advantage | Medical |
| Planned Not Authorized | Military and Defence |
| Passed Not Advanced | Military and Defence |
| Pamplona, Spain | Regional |
| Perth Netball Association | Sports |
| Phone Network Alliance | Telecommunication |
