| Rank | Abbreviation | Meaning |
|---|
| ***** | FSOS | For the Sake of the Salmon (est. 1995)
| |
| **** | FSOS | For Sale by Owner Services
| |
| **** | FSOS | Free Standing Operating System
| |
| *** | FSOS | food safety objectives
| |
| *** | FSOS | Foreign Service Officers
| |
| *** | FSOS | Family Support Orders Service
| |
| *** | FSOS | Food Service Operating Supplies
| |
| *** | FSOS | Friendly Sons of the Shillelagh
| |
| *** | FSOS | Financial Services Ombudsman Scheme
| |
| *** | FSOS | Flotilla Staff Officers
| |
| ** | FSOS | Free Space Optics
| |
| ** | FSOS | False Sense of Security
| |
| ** | FSOS | Flight Support Operations and Services
| |
| ** | FSOS | Fire Support Officers
| |
| * | FSOS | Flight Safety Officers
| |
| * | FSOS | Facility Security Officers
| |
| * | FSOS | Future Sounds of Swing
| |
| * | FSOS | First Step of Sarasota
| |
| * | FSOS | Family Support Organizations
| |
| * | FSOS | Family Service Office Supervisor
| |
| * | FSOS | Finite Set of Sentences
| |
| * | FSOS | Financial Services Offices
| |
| * | FSOS | Future Sound Of Sweden
| |
| * | FSOS | File System Objects
| |
| * | FSOS | Financial Services Ombud Schemes
| |