The SWP structure for the FID_CLIENT frame control, if present, is the last element of the pswp parameter, unless additional frame controls are added by subclassing; the SWP structures for these follow that for FID_CLIENT if present. The frame control window procedure first sends the message to the FID_CLIENT window. If FID_CLIENT returns ccount to indicate that the message has been processed, no additional processing is performed.

If not processed by the client, the frame control window procedure calculates the size and position of all the standard frame controls.