We have another one, of a different kind. My friend owns this ladies´ bicycle (aluminium frame with "EM" engravings, carbon fork, 3x8 Shimano group).

The frame numbers are:

Left side: P 0253
Right side: U06 1813 43

The system seems to be different from the one described in the first post of this thread. Do you have any knowledge of this? Thank you very much in advance!