When {HEAD ~ a request} to write {TAIL ~ the predetermined data} to the page again is received, the predetermined data is written to an empty free page in the log block 
When { HEAD ~ a request } to write { TAIL ~ the predetermined data } to the page again is received , the predetermined data is written to an empty free page in the log block
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH