| Abbreviation | Definition |
|---|---|
| MBFL | Marco's Bash Functions Library |
| MBL | Mouse Brain Library |
| MBPL | Miami Beach Public Library |
| MCDL | Mason County District Library |
| MCDL | Miguel de Cervantes Digital Library |
| MCFB | Michigan Center For the Book |
| MCFL | Marin County Free Library |
| MCL | Macomb County Library |
| MCL | Manchester Central Library |
| MCL | Medical Center Library |
| MCL | Mercer County Library |
| MCL | Multnomah County Library |
| MCL | My Color Library |
| MCLC | Maricopa County Library Council |
| MCLF | Marin County Library Foundation |
| MCN | American Journal of Maternal-Child Nursing |
| MCN | Media Catalogue Number |
| MCOP | Mechanics Corrections On Paper |
| MCPL | Marathon County Public Library |
| MCPL | Mason City Public Library |