{HEAD ~ The controller} can also use {TAIL ~ a random selection algorithm} in which the controller selects an access code at random from those stored in a memory list 
use
{ HEAD ~ The controller } can also use { TAIL ~ a random selection algorithm } in which the controller selects an access code at random from those stored in a memory list
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH