A few weeks ago, images began to surface online of an F-117 Nighthawk flying over Nevada and California. Despite being formally retired for more than a decade, a number of these aircraft are consistently maintained in flyable condition, prompting sporadic sightings over the years that never fail to get the aviation community buzzing.

This most recent sighting, however, came with a number of interesting details that aren’t as commonly seen on the rare occasions these birds get to spread their wings. Most notably, a series of unconfirmed reports state that at least four of these stealth aircraft were reactivated to fly combat missions over the Middle East as recently as 2017.

At least one F-117 was spotted conducting low-level, hard-banking maneuvers recently—a style of flying that runs contrary to the Nighthawk’s operational design (as a fairly slow moving, medium altitude, deep penetration bomber). F-16s were also spotted flying at a higher orbit over the area on opposing ends of the valley the F-117 was operating in. And now, perhaps most interesting of all, images snapped of the F-117 during these flights appear to show a tail band touting the name of a squadron that shouldn’t exist.

The band on the tail reads “Dark Knights,” which is a moniker normally associated with the Air Force’s 338th Training Squadron that specializes in airfield systems and ground radar. It seems unlikely that the 338th has anything to do with these F-117 flights, suggesting that their use of the name Dark Knights is probably unrelated.

The F-117 spotted wearing the Dark Knights tail band has had all other markings removed. So, assuming this Dark Knights squadron actually exists, what exactly does that mean?