I go to a Tokyo Joe's near my therapist's office often (1-2X a month) and, because it's almost always right after a therapist appointment, I'm at my most feminine (full makeup, a dress, & so on). The servers/cashiers are quite used to seeing me, and there's one woman in particular whom I usually chat briefly with -- so she's heard my totally male voice. I was there last week and had stepped away from the register without taking my metal number sign. She said "Ma'am!" to catch my attention. She knows I'm not a woman; she was just being respectful. I smiled and said "Thank you" and she smiled warmly back.