However, the authentication device or {HEAD ~ method} may also be used to authenticate a user to the remote service, or indeed, mutually authenticate a remote service and {TAIL ~ a user} 
used to mutually authenticate
However , the authentication device or { HEAD ~ method } may also be used to authenticate a user to the remote service , or indeed , mutually authenticate a remote service and { TAIL ~ a user }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL