Samlanka,How about the 'DOS Case ID'? is it the dv case number? Which applies same to all family members?
OR
It is the Immigrant visa case number, mentioned in visa lebel, which is different for all my family members?
I think only one case id for your family, because this is related to our case no that i won. Your passport it may be as 2013AS6XXX01, 2013AS6XXX02, etc, buy USCIS ask about sheet that was given by the embassy not from the passport. I am a single person, so don't know really it is.