France
 
French national police cap
Iíve always associated French policemen with the more traditional kepis, but about two months after I found this cap, I discovered that all the policemen who stamp passports and patrol Charles de Gaulle Airport in Paris wear this exact cap. Iíve wondered if the green cap band might be some kind of an international color-code for border police, since both the Soviet and East German border guards also used this color. Any thoughts?