| Abbreviation | Definition |
|---|---|
| IWP | Ignore Write Protect notch |
| JA | Jump if Above |
| JAA | Jump Almost Always |
| JAE | Jump If Above or Equal |
| JAL | Jump And Link |
| JAM | Jump And Move |
| JB | Jump if Below |
| JBE | Jump If Below or Equal |
| JBS | Jump and Blow Stack |
| JC | Jump if Carry |
| JCHA | Journal of the Commons House of Assembly |
| JCR | Jam Card Reader |
| JCXZ | Jump if CX Register Zero |
| JDEA | JunoCam Digital Electronics Assembly |
| JE | Jump If Equal |
| JEA | Jewish Educators Assembly |
| JECXZ | Jump if ECX Register Zero |
| JG | Jump If Greater |
| JGE | Jump If Greater or Equal |
| JIT | Just In Time (compiler) |