In {HEAD ~ another embodiment}, {TAIL ~ one substrate boat} may be interchangeably plugged into the other 
In { HEAD ~ another embodiment } , { TAIL ~ one substrate boat } may be interchangeably plugged into the other
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH