| WORD | NAME | DESCRIPTION | |
| MAR | Country IDs | Morocco | |
| MasterLP | Universe IDs - Other USA | Master Limited Partnerships | |
| MCO | Country IDs | Monaco | |
| MDA | Country IDs | Moldova | |
| MEX | Country IDs | Mexico | |
| MicroCap | Universe IDs - Other USA | MicroCap | |
| MidCap | Universe IDs - Other USA | Mid Cap | |
| MKD | Country IDs | Macedonia | |
| MLT | Country IDs | Malta | |
| MNE | Country IDs | Montenegro | |
| MNG | Country IDs | Mongolia | |
| MSR | Country IDs | Montserrat | |
| MUS | Country IDs | Mauritius | |
| MWI | Country IDs | Malawi | |
| MYS | Country IDs | Malaysia | |
| MYT | Country IDs | Mayotte |