As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(LOG 0877530) AFTER REMOVAL SIDE PLATE STA 500G+16 TO 500I LBL=24 WAS CORROSION FOUND ON UPPER FLANGE INTERCOSTAL AT FWD CARGO COMPARTMENT. INTERCOSTAL ON STA 500H TO 500I LBL=24 WAS FABRICATED AND REPLACED PER B737-800 SRM 53-30-53-0I PROCEDURE 2 IDENTIFICATION 2 AND B737-800 SRM 51-40-02-0G.