Often in research I find that individuals living in someone's house might be regarded as "children" of the family head (as indicated in some censuses) when in fact they were really cousins with the same surname. Before the truth can be sorted out, it would be good to be able to signify that a parent-child relationship is not a certainty by dotted or dashed line.
A visual indicator like that would help physically see within a genomap which relationships need further proof or research. Thanks! K. Scott Rimell