| Abbrev | Name | Spec | Type | Locality |
|---|---|---|---|---|
| MAN,2 | MANITOU[3733] | TR.AE | S | CAN |
| MANN | MANNING[3733] | TR.AE | W | USA:UT |
| MING | MARINGA[3733] | TR.AE | S | BRA |
| MMR | MARIS-MARDLER[3733] | TR.AE | W | GBR |
| MTMP | MARIS-TEMPLAR[3733] | TR.AE | W | GBR |
| MUI | MARROQUI[3733] | TR.AE | S | MAR |
| MSL,2 | MARSHALL[3733] | TR.AE | S | USA:MN |
| MASN | MASON[3733] | TR.AE | W | USA |
| MASS | MASSEY[3733] | TR.AE | W | USA:VI |
| MAV | MAVERICK[3733] | TR.AE | W | USA |
| MBS22 | MBS-1422[3733] | TR.AE | W | |
| MCC | MCCORMICK[3733] | TR.AE | W | USA:VI |
| M1003 | MCNAIR-1003[3733] | TR.AE | W | USA |
| M1813 | MCNAIR-1813[3733] | TR.AE | W | USA |
| M2203 | MCNAIR-2203[3733] | TR.AE | W | USA |
| M4823 | MCNAIR-4823[3733] | TR.AE | W | USA |
| M701 | MCNAIR-701[3733] | TR.AE | W | USA |
| MY,2 | MEALY[3733] | TR.AE | W | USA:NY |
| MG,2 | MENGAVI[3733] | TR.AE | S | AUS |
| MER,3 | MERIDIAN[3733] | TR.AE | W | USA:ID |