As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH INTO CVG BURNING RUBBER SMELL IN THE CABIN. EMERGENCY DECLARED, A/C LANDED SAFELY. RAN A/C AND OPERATED ENGINE BLEEDS NO SMELL NOTED, CHECKED INTERIOR LIGHTS AND GALLEY FANS AND HEATERS AS WELL AS GALLEY LIGHTS. NO ODORS NOTED.