| Abbreviation | Definition |
|---|---|
| IRD | Integer Real and Double |
| IRET | Interrupt Return |
| IRETD | Interrupt Return With EIP |
| ISC | Ignore System Crash |
| ISC | Interface Select Code |
| ISI | Increment and Skip on Infinity |
| ISLA | Image Sensor Lens Assembly |
| ISR | Interrupt Segment Register |
| ISR | Interrupt Service Routine |
| ISR | Interrupt Space Register |
| ISS | Inhibit Symmetrical Swapping |
| ITB | Instruction Template Buffer |
| ITE | If Then Else |
| ITOB | Write an Integer value TO a Binary string |
| ITOF | Convert Integer TO Floating point format |
| ITOZ | Convert Integer to Zoned format |
| IV | Integer Value |
| IVAR | Internal VARiable |
| IVB | Inclusive Value For Branch |
| IVR | Immediate Value Returned |