English abbreviations from irt to isa
- 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"))
- IS3 (In-transit Security and Survivability System)
- ISA (International Standard Atmosphere)
