For example, the internal features can serve to mechanically constrain {HEAD ~ internal parts} to {TAIL ~ the enclosure} 
to
For example , the internal features can serve to mechanically constrain { HEAD ~ internal parts } to { TAIL ~ the enclosure }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL