This is a unique symbol. It could indicate an individual. To understand completely its meaning, we must further context. Maybe it corresponds to a specific system. Looking into the where it came from of this symbol would be important. 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