Oh, I'm all in favor of not disclosing anything on the first date, even for CDers. Anyone would want to have a chance for at least friendship bonds to form, in order to make it easier to dispel the notion of stereotypes down the road. There's just way too much misinformation out there that is still believed by most people to be factual, to handle this any other way.
I suppose the question is rather when to tell ... third date? Three months? As has been mentioned above by several people, this has to be an individual decision based on individual circumstances and how quickly the relationships develop from the mere acquaintance stage.
Maybe I misread some of the people I thought were suggesting that it is not necessary to tell, ever, and this is why I asked my question.
