| Rank | Abbreviation | Meaning |
|---|
| ***** | NSSI | Non-Suicidal Self-Injury
| |
| ***** | NSSI | Nunavut Sealink and Supply Inc
| |
| **** | NSSI | Navigation Sensor System Interface
| |
| **** | NSSI | North Slope Science Initiative
| |
| **** | NSSI | National aeronautics and Space administration Science Internet
| |
| *** | NSSI | National Security Space Integration
| |
| *** | NSSI | National Security Space Institute
| |
| *** | NSSI | No Significant Schedule Impact
| |
| *** | NSSI | Network Security Solutions Inc
| |
| *** | NSSI | National Social Security Institution
| |
| *** | NSSI | Nuclear Safety/Security Inspection
| |
| ** | NSSI | Nicaraguan Social Security Institute
| |
| ** | NSSI | NAPCO Security Systems Inc
| |
| ** | NSSI | National Service Standards Instrument
| |
| ** | NSSI | Nuclear Sources and Services Inc
| |
| ** | NSSI | National Social Security Institute
| |
| * | NSSI | Natural and Social Science Interface
| |
| * | NSSI | Networking Security System Integration
| |
| * | NSSI | Needle Stick and Sharp Injuries
| |
| * | NSSI | National Student Services Inc
| |
| * | NSSI | national surety services inc
| |
| * | NSSI | National Switchgear Systems Incorporated
| |
| * | NSSI | Navrátil Software System Information
| |
| * | NSSI | New State Staff Inservice
| |
| * | NSSI | Newfield Staff Solutions International
| |