In Munich, it is quite hard to notice the ticket controllers before to hear their voice. Sometimes can be the guy sitting just next to you and asking you to present your ticket. Sometimes can be the guy in shorts, wearing an earring in his ear who got on the subway before you. You can meet him on Sunday evening, or on Thursday evening, at 23:30 when I come back from the bouldering gym. I can meet him almost every time.
In Munich, the ticket controller doesn’t have a working program or a uniform. He is just a normal guy, who can give smiling a fine, despite all the possible clarification. And I know very good that smile. I saw it already two times.
So, when you come to visit me, remember to have always a validate ticket with you.