As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT RETURNED TO IAH DUE TO A FLIGHT DECK WINDOW AIR LEAK. F/O SLIDING WINDOW LEAKED, AFTER TAKEOFF. F/O SLIDING WINDOW HAD AN AIR LEAK. FOUND CLIP LODGED IN WINDOW FRAME. REMOVED AND INSPECTED AREA AND FOUND NO DAMAGES. SEAL INTACT AND AS PRECAUTIONARY, DID PRESSURIZATION TO VERIFY LEAK, NO LEAK FOUND.