When the terminal transmits {HEAD ~ an attribute certificate issuance request message} in response to {TAIL ~ this message}, the terminal transmits an attribute certificate issuance message to the terminal  
When the terminal transmits { HEAD ~ an attribute certificate issuance request message } in response to { TAIL ~ this message } , the terminal transmits an attribute certificate issuance message to the terminal
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH