| Abbreviation | Definition |
|---|---|
| IRP | Integrated Resource Package |
| IRP | Integrated Resource Plan |
| IRP | Integrated Resource Planning |
| IRR | Information Request Response |
| IRS | identical, related, or similar |
| IRS | Identify, Reduce, and Schedule |
| IRS | Image Results And Security |
| IRS | Instant Refund Station |
| IRS | Internal Regulating Services |
| IRS | Inventory and Resource System |
| IS4S | Integrated Solutions For Systems |
| ISA | Information Sharing Assessment |
| ISB | Implementing the Strategic Blueprint |
| ISBN | International Standard Book Number |
| ISBO | Independent/Small Business Owner |
| ISBX | Integrated Service Business Exchange |
| ISC | Integrated Supply Chain |
| ISC | International Speedway Corporation |
| ISCI | ISA Security Compliance Institute |
| ISD | International Sales Division |