While I call all the Doms Sir I do not call them Master, even if it is part of their online screen name. So if someone came into the chatroom by the name of Master J, I would call Him J. The one exception is if I know that particular person is a Gorean master. Then I would continuously call Him Master J. That was what I was trained to do as a kajira. Even though I left Gor years ago, old habits die hard. But in real life the only Dom I call Master is my own. When meeting Doms in real life I call them Sir.