Once you live in south boston aka southie aka god's country for more than 10 years you become a "southie local" or a "local" for short.
If you move out to say Randolph the timer resets. However, once you hit 10 years you can move in and out as you please an not lose your local status.
Dan Kelly loved living in Randolph Mass and will gain his southie local status in 2025.