As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FA C & D INFORMED CREW AT THE GATE OF A STRONG ODOR EVENT AT ROWS 24 TO 26 FROM FL 20,000 TO LANDING. FOLLOWED TSM 05-50-00-810-831-A, LEVEL OF ODOR WAS IDENTIFIED AS LEVEL A. PERFORMED LEVEL A DECONTAMINATION IAW AMM 21-00-00. NO ODOR PRESENT DURING PROCESS.