As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5662 - DURING CLIMB THRU APPROX FL 180 LEFT REV UNLOCK MESSAGE CAME ON. FOLLOWED QRH AND RETURNED BACK TO PHF AND LANDED SAFELY. INSPECTED LEFT T/R AND STOW, DEPLOY AND THROTTLE LOCKOUT SWITCHES. ALL CHECKED GOOD. OPS CHECKED T/R, OPS CHECK GOOD.