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