{TAIL ~ a data pattern enforcer} for applying said rules to packets at {HEAD ~ the adaptor layer}; and 
{ TAIL ~ a data pattern enforcer } for applying said rules to packets at { HEAD ~ the adaptor layer } ; and
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH