The base quality layer 102 requires {HEAD ~ no keys} for access in {TAIL ~ implementations} in which the base quality layer 102 is unencrypted 
The base quality layer 102 requires { HEAD ~ no keys } for access in { TAIL ~ implementations } in which the base quality layer 102 is unencrypted
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH