| SIMG |
State Information Managers Group |
| SIMM |
Single Inline Memory Module |
| SIMP |
Strategic Information Management Plan |
| SIOM |
Server I/O Module |
| SIOP |
International Society of Paediatric Oncology |
| SIP |
Seasonal Irrigation Program |
| SIP |
State Implementation Plans |
| SIP |
Solar Influences Program |
| SIPRI |
Stockholm International Peace Research Institute |
| SIR |
Serial Infrared |
| SIR-A |
Shuttle Imaging Radar-A |
| SIR-B |
Shuttle Imaging Radar-B |
| SIRD |
Support Instrumentation Requirements Document |
| SIRR |
Software Integration Readiness Review |
| SIRTF |
Space Infrared Telescope Facility |
| SIS |
Simple Instruction Set |
| SIS |
Systems Integration Schedule |
| SIS |
Superconducting-Insulating Superconducting |
| SIS |
Standard Interface Specification |
| SIS |
Software Implementation Specification |
| SIS |
Simulator Interface System |
| SIS |
Shuttle Interface Simulator |
| SIS |
Shuttle Information System |
| SIS |
Serial Input Special |
| SIS |
Scanning Imaging Spectrometer |
| SIS |
SAIL Interface System |
| SIS |
Scientific Instrument Support Structure |
| SIS |
Species Information System |
| SISA |
Strategic Information Services Agreement |
| SISI |
Small Industries Services Institute |
| SISS |
STS Integrated Schedule Working Group |
| SISWG |
System Implementation Team |
| SIT |
Seal Initiation Temperature |
| SIT |
SSV Integrated Test |
| SIT |
Software Integrated Test |
| SIT |
Shuttle Interface Test |
| SIT |
Shuttle Integrated Test |
| SITA |
Suppression of Immoral Traffic in Women and Girls Act |
| SITA |
Societe Internationale De Telecommunications Aeronautiques |
| SITE |
Satellite Instruction Television Experiment |
| SITE |
Search For International Terrorist Entities |
| SITE |
Superfund Innovative Technology Evaluation |
| SITO |
Senior Information Technology Officer |
| SIU |
Signal Interface Unit |
| SIV |
Saturn IV Rocket |
| SIV-B |
Saturn IV-B Rocket |
| SIVE |
Shuttle Interface Verification Equipment |
| SIW |
Space Internet Workshop |
| SIW |
Soil and Irrigation Water |
| SJP |
Samajwadi Janata Party |