| Acronym | Definition |
|---|
| SIR➣School of International Relations (Iran) |
| SIR➣Society of Interventional Radiology |
| SIR➣Staten Island Railway (NY, formerly SIRT, Staten Island Rapid Transit) |
| SIR➣Self-Insured Retention |
| SIR➣Summary Information Return |
| SIR➣Spaceborne Imaging Radar |
| SIR➣Social Information Retrieval (various organizations) |
| SIR➣Scholar in Residence |
| SIR➣Social Indicators Research (various organizations) |
| SIR➣Shooting Incident Reconstruction (forensics) |
| SIR➣Security Intelligence Report (Microsoft threat analysis) |
| SIR➣Safety Information Registration |
| SIR➣Serial Infra Red |
| SIR➣Standard Infra Red |
| SIR➣Secondary Image Registration |
| SIR➣Save Instruction Recognition |
| SIR➣Security Intelligence Report |
| SIR➣Standardized Incidence Ratio |
| SIR➣Serial Infrared |
| SIR➣Signal-to-Interference Ratio |
| SIR➣Short Interest Ratio (finance) |
| SIR➣Surface Insulation Resistance |
| SIR➣Shuttle Imaging Radar |
| SIR➣Savings-to-Investment Ratio |
| SIR➣Statistical Inventory Reconciliation |
| SIR➣Specific Information Requirement (US DoD) |
| SIR➣Statement of Intent to Register (College) |
| SIR➣Screening Information Request (US FAA; same as RFP) |
| SIR➣Supplemental Inflatable Restraint |
| SIR➣Silent Information Regulator |
| SIR➣Serious Incident Report |
| SIR➣Single Instance Repository |
| SIR➣Statutory Invention Registration |
| SIR➣Society of Insurance Research |
| SIR➣Singapore Infantry Regiment |
| SIR➣Seattle International Raceway |
| SIR➣Special Investment Region (Dholera, Gujarat, India) |
| SIR➣System Impedance Ratio (power systems) |
| SIR➣Susceptible-Infected-Removed |
| SIR➣Social Investigation Report (Juvenile Justice Act; India) |
| SIR➣Société Ivoirienne de Raffinage (Abidjan, Ivory Coast) |
| SIR➣Security Incident Report |
| SIR➣Southeastern Institute of Research (ad survey firm) |
| SIR➣Starting Independent Researcher (European Research Council grant) |
| SIR➣Standard Indonesian Rubber |
| SIR➣Specific Insulation Resistance (electrical engineering) |
| SIR➣Sons In Retirement (Northern California retired men's luncheon club) |
| SIR➣Scientific Information Retrieval |
| SIR➣Selected Ion Recording (mass spectrometry) |
| SIR➣Singapore Immigration and Registration |
| SIR➣Statistical Information Retrieval |
| SIR➣Safeguards Implementation Report |
| SIR➣Stepped Impedance Resonator |
| SIR➣Speech Intelligibility Rating |
| SIR➣Safety Investigation Report |
| SIR➣Sequential Importance Resampling |
| SIR➣Sigma Iota Rho (international studies honorary society) |
| SIR➣Single Interactive Repository (computing) |
| SIR➣System Investigation Request |
| SIR➣Session Initiation Request |
| SIR➣Sample Inspection Report (engineering prototype) |
| SIR➣Snow and Ice on Runway |
| SIR➣Selective Integrated Rail System (law enforcement product) |
| SIR➣Supervised Intensive Restitution (Alabama prison program) |
| SIR➣Sorry If Repost |
| SIR➣Simulated Intelligence Robotics |
| SIR➣System Integration Review |
| SIR➣Spatial Impulse Response |
| SIR➣System Incident Report |
| SIR➣Submarine Intermediate Reactor |
| SIR➣Service Information Request |
| SIR➣Switched Integrated Rectifier (three phase transformer-rectifier power supply) |
| SIR➣Simple Indexing and Retrieval |
| SIR➣Standard Information Retrieval unit |
| SIR➣Systems Integrated Research (UK educational software firm) |
| SIR➣Standard-Issue Information Retrieval Unit (Invader Zim) |
| SIR➣Smooth Interpersonal Relationship |
| SIR➣Supplier Information Request |
| SIR➣Source Initiated Reservation |
| SIR➣Society of Individual Rights (1960s San Francisco homophile group) |
| SIR➣Skill Independent Regional (Visas) |
| SIR➣Scheduled Inspection and Repair |
| SIR➣Site Inspection Request |
| SIR➣Service Implementation Repository |
| SIR➣Semiannual Inventory Report |
| SIR➣Software Incident Report |
| SIR➣Sooner International Raceway |
| SIR➣Smith Industrial Rubber |
| SIR➣Sensitive, Intermediate, Resistant |
| SIR➣Safety Interlock Relay |
| SIR➣Set Iron Rod |
| SIR➣Sveriges Inredningsarkitekters Riksförbund |
| SIR➣Society of Independent Representatives Inc |
| SIR➣Search, Inspection & Recovery |
| SIR➣Sequential Independent Reviews |
| SIR➣Stored Information Retriever |
| SIR➣Special Inspection Requirement |
| SIR➣Special Investigative Requirement |
| SIR➣Surveillance Information Retrieval (gaming) |
| SIR➣Supervisor Investigation Reports (insurance) |
| SIR➣Scramble Intercept Recovery |