| Abbreviation | Definition |
|---|---|
| MHL | Medical History Library |
| MHLS | Mid Hudson Library System |
| MHPL | Medicine Hat Public Library |
| MHPL | Middle Haddam Public Library |
| MHPL | Minor Hill Public Library |
| MHPL | Morristown-Hamblen Public Library |
| MHPL | Mount Horeb Public Library |
| MHSL | Mervyn H Sterne Library |
| MI | Master Index |
| MIGI | Missouri Inter-library Group Initiative |
| MIL | Matrox Image Library |
| Mil.Med. | Military Medicine (serial publication) |
| MilitMed | Military Medicine |
| MILS | Maine InfoNet Library System |
| MIN | Manual Identification Number |
| MJML | Mary Johnston Memorial Library |
| MLA | Maryland Library Association |
| MLA | Massachusetts Library Association |
| MLA | Medical Library Association |
| MLA | Michigan Library Association |