Method and apparatus relating to an acknowledgement mechanism in an interconnected subsystem architecture. It allows M-PSK modulation for both beam polarizations. The visually checking portions are adjacent to the holding portions. For at least one disclosed embodiment, the structure may define one or more material support surfaces in an interior region of the container in addition to a bottom surface of the interior region of the container. That is, on the precondition that the active areas in n-channel MISFET formation regions are all configured in the isolated structure: the width of the terminal sections is made larger than the width of the central parts of the active areas.