| IRIG |
Inertial Rate Integrating Gyro |
| IRIS |
Intelligent Rotation In Space |
| IRIS |
Italian Research Interim Stage |
| IRIS |
Infrared Radiation Interferometer Spectrometer |
| IRL |
Intermediate Range Lander |
| IRL |
Initiating Reference Letter |
| IRL |
Interface Requirement List |
| IrLAP |
Infrared Link Access Protocol |
| IrLMP |
Infrared Link Management Protocol |
| IRM |
Integrated Resource Man |
| IRMA |
Intra-Retinal Microvascular Anomaly |
| IRMC |
International Radio Maritime Committee |
| IRME |
Initiator Resistance Measuring Equipment |
| IRMM |
Institute of Reference Materials and Measurements |
| IRMP |
Information Resources Management Plan |
| IRN |
Interface Revision Notice |
| IRNA |
Iranian News Agency |
| IRO |
International Refugee Organisation |
| IRP |
I/O Request Packet |
| IRP |
Iron Regulatory Protein |
| IRP |
Integrated Resource Planning |
| IrPHY |
Irda Serial Infrared Physical Layer Link Specification |
| IRPM |
Information Resource Program Manager |
| IrPnP |
Irda Plug And Play Extensions To Irlmp |
| IRPP |
Institute For Research On Public Policy |
| IRQ |
Interrupt Request |
| IRQL |
Interrupt Request Level |
| IRR |
Institute of Restoration and Reclamation |
| IRR |
Inspection Rejection Report |
| IRR |
Integral Rocket Ramjet |
| IRR |
Ionising Radiation Regulations |
| IRRI |
International Rice Research Institute |
| IRRO |
Indian Reprographic Rights Organization |
| IRS |
Indian Revenue Service |
| IRS |
Indian Remote Sensing Satellite; Indian Revenue Service |
| IRS |
Insulin Receptor Substrate |
| IRS |
Insulin Resistance Syndrome |
| IRS |
Inertial Reference System |
| IRS |
International Relief Service |
| IrTinyTP |
Infrared Tiny Transport Protocol |
| IRTS |
Indian Railway Traffic Service |
| IRU |
Inertial Reference Unit |
| IRV |
Inspiratory Reserve Volume |
| IRV |
Improved Inter-Range Vector |
| IRV |
Isotope Reentry Vehicle |
| IRV |
Incident Response Vehicle |
| IS |
In Situ |
| IS |
Intercostal Space |
| IS |
Information Systems |
| ISA |
Industry Standard Architecture |