This represents a unique symbol. It suggests an individual. To understand completely its meaning, we must further context. Maybe it corresponds to a specific system. Looking into the origin of this code would be helpful. Truc Tiep Da Ga Thomo 2023 Thoi gian den tai/vào/cho ??n ngay thang/ngày tháng/ngày/ 15/m??i l?m/n?m m??i l?m thang