PLN
- Liberal Nationalist Party
- National Liberal Party (Panama)
- National Liberation Party (Costa Rica)
- P. L. N. Padfield
- Palenquero
- Pellston Regional Airport
- Personal learning network
- Perusahaan Listrik Negara
- Phospholamban
- Picton, Lennox and Nueva
- Plan (disambiguation)
- Planetary nebula
- Pleione (plant)
- Polish złoty
- Port letter and number
- Probabilistic logic network
- SilkTest