| Abbreviation | Definition |
|---|---|
| MCS | Modify Comment Section |
| MD | Machine Dependent |
| MDNF | Medical Device Numeric Format |
| MDX | Modify Index |
| ME | Make an Error |
| ME | Method Entry |
| MEF | Mask Error Factor |
| MF | Method Flag |
| MFC | Merge From Current |
| MFS | Move From Segment |
| MI | Machine Interface |
| MI | Maskable Interrupt |
| MI | Micro Instruction |
| MIO | Module Input Output |
| MKI | Merge Kernel Interface |
| ML | Machine Language |
| ML | Make And Link |
| MLR | Move and Lose Record |
| MLS | Maximum Long String |
| MM | Move Memory |