Clients, for the most part, use their given names rather than the message center handle. Escorts are a more mixed bag, if their escort name is a "normal" name, such as Tom, Dick or Harry then I found that to be the name used, however if it is not what would be considered "normal" then they they will introduce themselves as Tom, Dick or Harry, which may or may not be their given name. It is left to each individual to introduce themselves by the name they wish to be known as.