As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL - FLT 796 EN ROUTE PHL TO TLV. AFTER TAKEOFF, THE CREW NOTICED A PUNGENT ODOR. AFTER CYCLING THE PACKS, IT WAS DECIDED THAT THE ODOR WAS COMING FROM ONE OF THEM. THE FLIGHT RETURNED TO PHL AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE ACTION IS PENDING.