English abbreviations from irs to is
- IRS (Inertial Reference System)
- IRSA ((organization) Infrared Science Archive)
- IRSN (Institut de radioprotection et de sûreté nucléaire (French, "Institute for Radiation Protection and Nuclear Safety"))
- IRST (Infra-red Search and Track)
- IRSTS (Infrared Search and Track Sensor)
- IRT ("in reference to...")
- IRTA (Intramural Research Training Award)
- IRTC (International Rolling Technology Course)
- IRTC-1 (Interconnect Reliability Test Chip-1)
- IRTF ((telescope) InfraRed Telescope Facility)
- IRTJ (IRTJ Gamma Ray Slimhole Log)
- IRTT (Initial Round Trip Time)
- IRU (Inertial Reference Unit)
- IRV (Ideal Resting Value)
- IRW (Islamic Relief Worldwide)
- IRWI (International Research Watch International)
- IRWIL (I Read What I Like)
- IRX ((astrophysical terminology) InfraRed Excess)
- IS (Information System)
- Is. (Idus ("Ides"))