Register for and method of providing contact information for {HEAD ~ a communications unit} identified by {TAIL ~ a uniform resource name} 
Register for and method of providing contact information for { HEAD ~ a communications unit } identified by { TAIL ~ a uniform resource name }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL