Hi Ann Thank you for posting that information. It is taking me a bit to understand all the terminology. I am still struggling with what the plus side is? I guess this doesn't matter .. In my case I have Dad's and my DNA. If the match is listed with Dad and me it belongs to his side of the family. If the match isn't listed with Dad than it could be Mum's side[if over 10cMs] or IBS. If a segment I have in common with Dad matches me with someone but not Dad, I can check base pairs from the Raw Data, to determine if it matches Mum's bases or if it is IBS. Is IBS when the match has mixed bases some from Dad and some from what would be Mum? Is IBD when all the bases match only Dad's or match what would have been only Mum's bases? Karen FF is > always reporting one side of the double helix (called the plus side). The > two bases you see in the raw data are from the two copies of the > chromosomes, the maternal and the paternal (each one is a separate double > helix).