I have never deliberately approached a provider, but there was an instance once when I was at a flea market and saw someome I knew as a provider walking towards me. In that case I already knew her real name because she had given it to me previously. She greeted me by name, so I also greeted her by name, we exchanged the normal "how have you been" pleasantries and then went on our separate ways with no references to how we knew each other from the past.