sort by Rank | Alpha
| Possible Meanings | Rank |
|---|
| Progress Open Source Software Exchange | *** |
| Preserve Our Student Shows for Eternity | ** |
| Portable Open Source Security Elements | ** |
| Pluto and Outer Solar System Explorer | ** |
| Photonics Optics Summit and Special Event | ** |
| Peer Observation Support and Self Evaluation | * |
| Peers Organized to Support Student Excellence | * |