According to Production Weekly, the filming production code name for Wonder Woman is “Nightingale”.
Film’s having production code names aren’t unheard of, as both Batman v Superman: Dawn of Justice and Suicide Squad also had them. Sage and Milo for Batman v Superman and Bravo 14 for Suicide Squad.
Production code names is the studio’s way of protecting their films from having information leaked out as they work on the film during the pre-production period.
The fact we now know what the production code name for Wonder Woman is at this moment in time, only means that we’re just that much closer to getting the good stuff!