As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING DESCENT THROUGH 40000' F/A REPORTED "DIRTY SOCK" SMELL IN AFT CABIN. APU WAS OFF. CHECK-LIST PERFORMED. SMELL WAS THEN REPORTED AS VERY FAINT-TROUBLESHOT IAW TSM 05-50-00-810-831-A. FOUND APU TO BE SORCE OF AIR QUALITY EVENT. SEE LP 2810952-02 FOR APU DEFERRAL