| Abbreviation | Definition |
|---|---|
| JL | John Lincoln |
| JL | Juan Lopez |
| JL | Judy Lynn |
| JL | Juli Lennon |
| JLB | Johnny Long Boots |
| JM | Jacob Martin |
| JM | James Matthew |
| JM | Jean Marc |
| JM | Jean Marie |
| JM | Jean Michel |
| JM | Jeffery Michael |
| JM | Jon Michael |
| JMGB | José María González Blanch |
| JMGB | Juan Manuel Grau y Berrío |
| JMY | Jimmy |
| JN | John Nelson |
| JN | John Newton |
| JN | Joseph Nelson |
| JOEY | Joseph |
| JON | Jonathan |