This forms {TAIL ~ a cutout} or depression for at least one guide segment of {HEAD ~ the guide device} 
This forms { TAIL ~ a cutout } or depression for at least one guide segment of { HEAD ~ the guide device }
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD