| Abbreviation | Definition |
|---|---|
| SHRD | Super High-Resolution Display |
| SHS | Super Hybrid Sensor |
| SHSA | Ship Serviceman Seaman Apprentice |
| SHSM | System High Security Mode |
| SHSN | Ship Serviceman Seaman |
| SHTF | Shit Hit The Fan |
| S-HTTP | Secure Hyper Text Transfer Protocol |
| SHTU | Simplified Hand held Terminal Unit |
| SHTU | Simplified Hand-held Terminal Unit |
| SHU | Security Housing Unit |
| SHWM | System High Water Mark |
| SI | Scientific Intelligence |
| SI | Space Intelligence |
| SI | Space Intelligency |
| SI | Special Intelligence |
| SI | Special Interest |
| SI | Support Installation |
| SI | System Integration |
| SI | United States Strategic Command Strategic Instruction |
| SIA | Station of Initial Assignment |