The drain region, {TAIL ~ the source/base region}, and the cathode region have {HEAD ~ a second conductivity type} 
The drain region , { TAIL ~ the source / base region } , and the cathode region have { HEAD ~ a second conductivity type }
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD