In case there are {HEAD ~ different security classes} among end user devices of the same group, the L2 network access tier devices may sub divide the group or more assign the lowest security class to the group to which {TAIL ~ the most vulnerable end user device} conforms 
In case there are { HEAD ~ different security classes } among end user devices of the same group , the L2 network access tier devices may sub divide the group or more assign the lowest security class to the group to which { TAIL ~ the most vulnerable end user device } conforms
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH