As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIRTY SOCK SMELL FROM INITIAL DESCENT TO THE GATE. PERFORM TSM 05-50-00-810-831-A IDENTIFACTION OF THE CAUSE OF CABIN ODOR. ENGINE #1 & ENGINE #2 OK APU OK BOTH PACK OIL AND NO HYDRAULIC LEAK. THE CAUSE TYPE A IS MISCELLANEOUS FOUND THE SMELL COMING FROM THE FORWARD LAV. AIRCRAFT OK FOR SERVICE.