Group names - Global-Conflicts-ArmA/Olsen-Framework-Arma-3 GitHub Wiki
Custom group names are really important since they clear up all confusion about what squad people are in.
Custom group names are handled by the gear script. It has to be set on every squad member, to make sure that even if only 1 guy slots into the squad, the custom group name will still be displayed.
The following line is put into the initialization field of the unit, please see gear script.
Example:
[this, "SL", "1'6"] call FNC_GearScript;