As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BURNING RUBBER ODOR IN THE AFT CABIN. INSPECTIONS HAVE BEEN ACCOMPLISHED IAW AMM 05-51 -58. NO FURTHER ODOR COULD BE FOUND. CAPTAIN AND FLIGHT ATTENDANTS REPORTED THAT ODOR COMES AND GOES VERY INFREQUENTLY AND IN 10-20 SECOND INCREMENTS. NO PREVIOUS HISTORY. NO FURTHER DEFECTS FOUND.