I asked a couple people back in May when this came up before, but no one really knows, unless Craig has an idea... only thing that makes sense to me is maybe organizational, maybe regional or city-town, like EWB Passau or EWB München, like some of the arm bands they wore? It it were PU / EWB that would make some sense, or is there a town or region that PZ fits in Bavaria? Can't think of one...