User interface 520 may include mechanisms for inputting {HEAD ~ information} to {TAIL ~ user device} 210 and for outputting information from user device 210 
to
User interface 520 may include mechanisms for inputting { HEAD ~ information } to { TAIL ~ user device } 210 and for outputting information from user device 210
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH