| Abbreviation | Definition |
|---|---|
| IEF | Image Exchange Format Bitmap graphics |
| IFD | JetForm Design Form |
| IFF | Bitmap graphics or sound (Amiga IFF/8SVX Interchange File Format) |
| IFF | Image File Format |
| IFF | Sun TAAC Image File Format Bitmap graphics |
| IFP | KnowledgeMan Script |
| IFS | Fractal image compressed file (YuvPak) |
| IFS | FRACTINT Iterated Function System Fractal |
| IFS | Installable file system (OS/2) |
| IG | Generic interface source (Modula-3) |
| IGES | 2D or 3D CAD model (Initial Graphics Exchange Specification format) |
| IGF | Inset Systems metafile |
| IGS | 2D or 3D CAD model Initial Graphics Exchange Specification format |
| IGS | Image Systems Grayscale |
| IHP | Help file (Watcom) |
| IHS | Inbound History (Bink/+) |
| II | Preprocessed C++ source code (gcc) |
| IIF | Interchange File ( QuickBooks for Windows) |
| IIF | Intuit Interchange Format |
| IL | hDC Designer Icon Lin Dll format |