| Abbreviation | Definition |
|---|---|
| MRSL | Minnesota Recreational Soccer League |
| MS | Men's Soccer |
| MSMSL | Metro Senior Mens Soccer League |
| MSPSL | Michigan State Premier Soccer League |
| MSPSP | Michigan State Premier Soccer Program |
| MSRA | Michiana Soccer Referees Association |
| MSSA | Maryland State Soccer Association |
| MSSL | Maryland Super Soccer League |
| MSSL | Massachusetts State Soccer League |
| MTSC | Manheim Township Soccer Club |
| MTSC | Metro Tulsa Soccer Club |
| MTSC | Monroe Township Soccer Club |
| MTSC | Montgomery Travelers Soccer Club |
| MUSA | Madison United Soccer Association |
| MUSA | Marshall United Soccer Association |
| MUSC | Milford United Soccer Club |
| MUSC | Mountaineer United Soccer Club |
| MUSL | Michigan United Soccer League |
| MUSS | Manchester United Soccer School |
| MUSS | Manchester United Soccer Schools |