Seeed Production code" 01895Q-Dxxxxx-dd / 10220a-Dxxxxx " MUST be printed automatically on empty space or the edge of your PCB (height 0.75-1.0mm; wire thickness 0.15mm), no matter on the top side or bottom side. It is used for production record and can be traced if there is a quality problem.
Please be aware of that. Sorry for the inconvenience
Note: "xxxxx" is seeed order file NO. and "dd" is the finished date.